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MILTON  M.   LEONARD,   D.V.M, 


NORTH  CAROLINA  STATE  UNIVERSITY  LIBRARIES 


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Tte  Plural  SctencB  S:eri;es 

Edited  by  L.  H.  Bailey 


MILK    AND    ITS    PRODUCTS 


■•1^>^° 


MILK  AND  ITS  PRODUCTS 


A  TREATISE  UPON  THE  NATURE  AND  QUALITIES  OF 

DAIRY  MILK  AND  THE  MANUFACTURE 

OF  BUTTER  AND  CHEESE 


BY 

HENEY  H.  WING 

Assistant  Professor  of  Dairy  Husbandry 
IN  THE  Cornell  University 


FIFTH    EDITION 


THE   MACMILLAN   COMPANY 

LONDON:    MACMILLAN  &  CO.,  Ltd. 

1902 

All  rights  rrsicrved 


Copyright,  1897 
By   HEXRY  H.  wing 


Set  up  and  eleetrotyped  Februarj-,  1897 

Reprinted  with  corrections  February,  189S,  July,  1S99 

July,  1000,  January,  1902 


^ount   IlDIeaisant    CDreso 
J.  Horace  McFarland  Company 

H  AR  R  I  S  B  U  R  G   •  P  £  X  N  S  Y  LVAN  lA 


Ta  mv  futhtx 

AS   A   SLIGHT   TRIBUTE   TO   THE   CAREFUL   TRAINING   AND 
WISE   AND    SYMPATHETIC   COUNSEL   THAT 
SERVED    TO    INSTIL   IN   THREE   FARM    BOYS   A    LOVE    FOR   ALL 
THAT    PERTAINS   TO   FARM    LIFE 

Tlris  little  mark  is  rtfftctmnuUlg   instribH 


(V) 


PEEFACE. 

The  revolution  in  dairy  practice  brought  about 
by  the  introduction  of  the  centrifugal  cream  sepa- 
rator and  the  Babcoek  test  for  fat  and  by  a  more 
definite  knowledge  regarding  the  various  fermenta- 
tions that  so  greatl}'  influence  milk  and  the  manu- 
facture of  its  products,  has  seemed  to  demand  the 
publication  of  a  small  handbook  that  shall  give 
to  the  dairyman,  and  particularly  to  the  dairy 
student,  in  simple,  concise  form,  the  principles  un- 
derlying modern  dairy  practice.  In  attempting  to 
meet  this  demand,  I  have  had  largely  in  view  the 
needs  of  my  own  students,  while  still  keeping  in 
mind    the    general    dairy   reader. 

In  the  colhition  of  the  information,  where  so 
many  points  are  still  unsettled,  it  is  of  course  dif- 
ficult in  all  cases  to  distinguish  fact  from  conjec- 
ture. The  aim  has  been  at  all  times  to  give 
the  present  state  of  knowledge  as  supported  by 
the  weight  of  evidence  and  the  opinions  of  those 
whose  authority  is  highest.  In  how  far  this  has 
been    successful    time    alone    can    tell.       It   would    be 

(vii) 


viii  Preface. 

too    miieli  to    hope    that    every    coiielusiou   will    stand 
the    test    of   further   investigation    and   experience. 

Dairy  practice  in  the  United  States  owes  mnch 
to  the  investigations  of  the  Agricultural  Experiment 
Stations,  Of  the  results  of  their  labor  free  use 
has  been  made  in  various  ways,  and  in  many  cases 
without  specific  mention  at  the  particular  i)lace. 
Without  wishing  to  make  distinctions,  particular 
acknowledgment  is  here  rendered  to  the  reports 
and  bulletins  of  the  Stations  in  Maine,  New  Hamp- 
shii-e,  Vermont,  Connecticut  (Storrs),  Canada,  New 
York  (State),  New  York  (Cornell),  New  Jersey, 
Pennsylvania,  Illinois,  Iowa,  Wisconsin  and  Minne- 
sota. For  those  who  wish  to  make  more  extended 
investigations,  a  bibliography  is  added  in  the  Ap- 
pendix, giving   references   to   many   bulletins. 

Thanks  are  due  to  D.  H.  Burrell  &  Co.,  the 
Vermont  Farm  Machine  Co.,  the  DeLaval  Separator 
Co.,  the  Star  Milk  Cooler  Co.,  the  Champion  Milk 
Cooler  Co.,  J.  F.  Hodgkin,  and  F.  B.  Fargo  &  Co., 
for   the    use    of    electrotypes. 

Acknowledgment  is  also  due  my  colleagues, 
Messrs.  Cavanaugh,  Durand,  Hall  and  VanWagenen, 
for  valuable  assistance,  and  to  Professor  L.  H, 
Bailey  for  much  friendly  counsel  and  many  useful 
suggestions. 

HENRY    H.  WING. 

Cornell  University  Dairy, 
January    1897. 


CONTENTS. 

CHAPTER    I. 

Secretion    of    Milk. 

Milk  defined  — Mammary  glands— Udder  — Internal  structure  of 
udder  and  teats —Ultimate  follicle  —  Secretion  of  milk— In- 
centives to  secretion  —  Amount  and  duration  of  flow  —  Effect 
of  succeeding  pregnancy  —  Incomplete  removal  of  milk  — Reg- 
ularity and  frequency  of  milking  — Control  of  animal  over 
secretion. 

Pages  1-15 

CHAPTER   II. 

Composition  of  Milk. 

Milk  constituents  — Colostrum  — Specific  gravity  — The  fats— The 
volatile  fats  — The  non-volatile  fats  — The  albuminoids  —  The 
sugar  — The  ash  — Other  constituents  —  Variations  in  quality 
of  milk. 

Pages  16-34 

CHAPTER    III. 

The  Testing  of  Milk. 

Gravimetric  analysis  — History  of  milk  tests  — Cream  gauges  — 
Specific  gravity  —  Lactometers  —  Churn  tests  —  Lactobutyro  - 
meter  —  Pioseope  —  Lactoscope  —  Soxhlet's  method  —  Lacto- 
crite  — Fjord's  control  apparatus  — Milk  tests  in  the  United 
States  — Short's  method  —  Method  of  Failyer  and  Willard  — 


X  Contents. 

Parsons'  method  —  Iowa  Station  tost  —  Cochran's  method  — 
Babcoek  test  —  Beimling  test  —  Gerber's  method  —  Butyrom- 
eter  —  Details  of  Babcoek  test  —  The  centrifugal  machine  — 
The  glassware  —  Sampling  the  milk  —  Composite  sampling  — 
Making  the  test  —  The  acid  —  Whirling  —  Reading — Cleaning 
the  glassware. 

Pages  35-65 

CHAPTER    IV. 

The  Ferments  and  Fermentations  of    Milk  and 
Their  Control. 

Tendency  to  undergo  change  —  Germs  of  fermentation  — Bacteria  — 
Presence  of  bacteria  in  milk  —  Kinds  of  bacteria  in  milk  — 
Fermentations  of  milk  —  Relation  of  milk  bacteria  to  the 
human  system  —  Lactic  fermentations  —  Fermentations  affect- 
ing the  albuminoids  —  Butyric  fermentations  — Control  of  fer- 
mentations—  Prevention  of  infection  —  Holding  at  low  tem- 
peratures—  Destruction  of  germs  in  milk  —  Pasteurization  — 
Selection  of  milk  for  pasteurization. 

Pages  66-82 

CHAPTER   V. 
Market  Milk. 

Milk  for  consumption  —  Cleanliness — Treatment  after  drawing  — 
Aeration  —  Delivery  —  Bad  flavors  in  milk  —  Quality  of  milk 
for  consumption  —  Control  of  milk  supply  —  Cream  for  con- 
sumption^— -Pasteurized  cream  —  Quality  of  cream. 

Pages  83-96 

CHAPTER    VI. 

Separation  of  Cream. 

Gravity  creaming —  Shallow-pan  creaming  — Deep  setting  system- 
Centrifugal  separation  —  Conditions  affecting  completeness  of 
separation  —  Conditions  affecting  the  relative  amount  of 
skimmed    milk    and    cream  —  Contrivances    in   the    bowl    to 


Contents. 


XI 


increase  the  efficiency  of  separation — Mechanical  conditions 
affecting  separation  —  Efficiency  of  separation  in  centrif- 
ugal machines — Desirable  and  undesirable  features  of  a  sep- 
arator. 

Pages  97-126 

CHAPTER    VII. 

The  Ripening  op  Cream. 

Means  of  producing  lactic  acid  —  Temperature  of  ripening  — 
Amount  of  acid  necessary — Acid  tests  —  Determination  of 
lactic  acid  in  milk  and  cream — Further  effects  of  ripening — 
Churning  cream  of  different  degrees  of  ripeness — Bad  effects 
of  over-ripening. 

Pages  127-139 

CHAPTER    VIII. 

Churning. 

Viscosity  of  the  milk — Ripeness  of  cream — Temperature — Nature 
of  agitation— Quality  of  the  globules  of  fat — End  of  churn- 
ing— Difficult  churning. 

Pages  140-149 

CHAPTER    IX. 

Finishing  and  Marketing  Butter. 

Washing  the  butter — Working  —  Salting  —  Brine  salting  —  Pack- 
ing and  marketing — Composition  and  quality  of  butter. 

Pages  150-162 

CHAPTER   X. 

Milk  for  Cheese  Making. 

Theory  of  cheese  making — Quality  of  milk  for  cheese  making — 
Loss  of  fat— Cooling— Aeration — Ripening — Rennet  tests- 
Degree  of  ripeness  necessary — Starters  —  Rennet  —  Removal 
of  whey. 

Pages  163-180 


xii  Contents. 

CHAPTER    XI. 

Cheddar  Cheese  Making. 
Setting  —  Cutting  —  Heating  —  Cheddaring  —  Grinding— Salting  — 
Curing  — DiflSculties  likely  to  occur  in  cheddar  cheese  mak- 
ing—  Qualities  of  Cheese. 

Pages  181-198 

CHAPTER   Xn. 

Varieties  of  Cheese. 
Home-trade  or  stirred-eurd  cheese — Sage  cheese  —  Young  Amer- 
ica— Picnics  —  Pineapple — Truckle  —  American  Neuf  ehatel  — 
Philadelphia  cream  cheese  —  Limburger — Imitation  Swiss  — 
Prepared  cheese  —  English  cheese— Stilton  —  Cheshire  — 
Lancashire  —  Derbj^shire  —  Leicestershire  —  Wensleydale  — 
Gorgonzola  —  Emmenthaler  or  Swiss  —  Edam — Gouda  — 
Roquefort — Brie  —  Camembert  —  D'Isigny  —  Pont  L'Eveque  — 
Port  du  Salut  —  Parmesan. 

Pages  199-228 
CHAPTER   XIII. 

By-Products  of  the  Dairy. 
Skimmed     milk,    buttermilk    and    whey  —  Dried     Casein  —  Milk 
sugar  —  Dutch    cheese  —  Whey   cheese  —  Cheese    food  —  Kou- 
miss —  Kephir  —  Wheyn. 

Pages  229-235 

CHAPTER    XIY. 
Butter  and  Cheese  Factories. 
Location   of   creameries  —  Arrangement    of   building  —  Construc- 
tion—  Cheese    factories — Combined    butter  and    cheese    fac- 
tories—  Farm  dairy  buildings. 

Pages  236-247 

CHAPTER   XV. 
Statistics  and  Economics  of  the  Dairy  Industry. 
Increase  in  dairy  production  —  Development  of  the  factory  sys- 
tem—Condensed milk  —  Dairy  legislation  —  Dairy  markets. 

Pages  248-258 


Contents.  xiii 

APPENDIX. 

A.  Useful  rules  and  tests. 

Pages  259-266 

B.  Metric  system  of  weights  and  measures. 

Pages  267-268 

C  Legal  standards  for  milk  in  the  various  states  —  The  oleomar- 
garine law  —  The  filled-eheese  law — The  New  York  state 
dairy  law. 

Pages  269-288 

D,  References  to  Agricultural  Experiment  Station  reports  and 
bulletins. 

Pages  289-297 
INDEX. 

Pages  299-311 


Udders  of  good   and   poor  types. 

From   Bulletin   No.  62.  Purdue   Univ.  Agr.  Exp.  8ta.,  by   permission. 

See  page  3. 


MILK  AND  ITS  PRODUCTS, 


CHAPTER   I. 


THE   SECRETION   OF  MILK. 

The  females  of  all  animals  that  suckle  their 
young  (class  Mammalia)  secrete  for  this  purpose  a 
special  fluid  which  is  known  as  milk.  It  is  an 
opaque  yellowish  white  fluid,  with  a  slight  alkaline 
reaction  and  a  faintly  sweetish  taste.  It  consists 
of  an  emulsion  of  fats  in  a  watery  solution  of 
alkaline  salts,  casein  and  sugar.  It  is  secreted  in 
two  special  glands  situated  without  the  body  cavity 
on  either  side  of  the  median  line,  and  known  as 
the   mammary   glands    or    mammae. 

Mammarij  glands. — While,  strictly  speaking,  there 
are  but  two  glands,  each  gland  may  be  divided 
into  two  or  more  lobes,  each  having  a  separate  open- 
ing.; thus,  while  thei^e  are  ordinarily  but  two  simple 
glands  in  the  ewe,  mare  and  goat,  in  the  cow  there 
are  four  or  six,  in  the  cat  and  bitch  six  to  ten,  and 
in  the  sow  ten  to  fourteen.  In  animals  having 
multiple  glands,  the  mammse  occupy  nearl}^  the  whole 
of  the  lower  part  of  the  chest  and  abdomen.  In 
other  animals  the  glands  are  confined  either  to  the 
chest    or    abdomen.       In    many   animals    each    gland 


2  MilJc   and   Its   Products. 

or  lobe  is  furnished  with  a  single  opening  connect- 
ing with  a  single  duct,  in  others  several  ducts 
open  independently  upon  the  surface  of  a  single 
nipple  or  teat.  The  mammary  gland  is  a  true 
organ  of  secretion  in  the  sense  that  its  product  (milk) 
contains  substances  not  before  existing  in  the  blood, 
that  are  formed  during  the  process  of  secretion  in  the 
gland  itself.  In  the  cow  the  mammarj^  glands  are  lo- 
cated on  the  posterior  portion  of  the  abdomen  be- 
tween the  hind  legs,  and  each  gland  is  made  up  of 
two  lobes  or  quarters,  each  having  a  single  outlet 
furnished  with  a  single  duct,  though  there  are  often 
one  and  sometimes  two  rudimentary  ducts  upon  the 
rear  quarters,  and  which  are  occasionally  developed  to 
such  an  extent  that  milk  may  be  drawn  from  them 
in  small  quantities.  The  whole  organ  is  spoken  of  as 
the  udder,  and  the  ducts  as  teats.  While  the  mam- 
mary gland  is  essentially  a  female  organ,  it  is  present 
in  a  rudimentary  condition  in  the  males  of  all  mam- 
rnals,  and  in  exceptional  cases  in  man  and  in  the  lower 
animals  the  organs  of  males  have  developed  to  such  a 
degree  as  to  secrete  milk. 

The  cotv^s  udder. — The  udder  is  enclosed  in  a  fold 
of  skin,  which  is  here  thinner  and  softer  than  upon 
other  parts  of  the  body,  and  is  supported  by  a  band 
of  fibrous  tissue  that  springs  from  the  median  line  of 
the  body  and  extends  through  the  whole  substance  of 
the  gland.  It  varies  very  much  in  size  and  shape 
in  different  animals  and  in  the  same  animal  at  dif- 
ferent times.  Its  size  is  not  always  an  indication 
of   the  secreting  powers  of  an  animal,  since  the  num- 


structure   of  tlie    Udder.  3 

ber  of  true  secreting  follicles  does  not  necessarily  bear 
any  relation  to  the  apparent  siz«.  The  udder  in  a 
good  cow  should  be  large  and  well  developed ;  it 
should  occupy  the  whole  space  between  the  hind 
legs,  extending  well  up  between  the  thighs  and 
well  forward  upon  the  belly.  It  should  be  held 
firmly  against  the  wall  of  the  abdomen.  It  should 
be  level  or  nearly  so  on  the  bottom,  "and  the  four 
quarters  should  be  as  nearly  as  possible  equally 
developed  and  each  furnished  with  a  cylindrical  per- 
pendicular teat  of  moderate  length.  The  whole 
organ  should  diminish  rapidly  in  size  as  the  milk 
is  withdrawn.  The  hair  upon  the  udder  should  be 
fairly  abundant,  fine  and  soft,  and  abundantly  sup- 
plied  with   a   brownish    dandruff. 

The  substance  of  the  udder  is  composed  of  the 
fibrous  band,  already  mentioned,  connective  tissue, 
fatty  tissue,  milk  ducts  or  canals,  true  secreting 
cells  (acini,  ultimate  follicles,  alveoli),  veins,  arte- 
ries, nerves  and  lymphatics,  the  whole  making  up  a 
reddish   gray   mass   of   spongy   texture. 

The  udder  varies  very  much,  in  different  indi- 
viduals, in  size  and  shape  as  well  as  in  internal 
structure  and  secreting  capacity.  In  some  animals 
the  amount  of  connective  and  fatty  tissue  is  much 
larger  than  in  others.  Such  udders  are  said  to  be 
"fleshy,"  and  while  usually  of  large  size  and  good 
shape,  are  deficient  in  true  secreting  capacity.  They 
are  firm  to  the  touch,  particularly  when  empty,  and 
do  not  markedly  diminish  in  size  when  the  milk 
is   withdrawn.       It    is   generally   supposed    that    such 


4  Milk   and   Its   Products. 

udders  are  more  subject  to  inflammations  and  in- 
flammatory diseases  than  those  with  less  fatty  tissue. 
In  many  cows  the  fibrous  net -work  that  supports 
the  udder  is  held  firmly  up  to  the  under  side  of  the 
abdomen.  If,  in  connection  with  this,  the  udder  has 
comparatively  little  connective  and  fatty  tissue,  the 
animal  will  have  an  udder  apparently  small,  but  with 
large  capacity  for  secretion.  In  old  cows,  particu- 
larly those  that  have  been  large  milkers,  the  fibrous 
bands  often  become  largely  relaxed,  so  that  the 
udder  falls  nearly  to  the  ground,  and  appears  to  be 
of   enormous  size. 

Internal  structure  of  the  udder  and  teats.  —  The 
teat  is  simply  a  canal  surrounded  by  muscular  walls 
and  closed  at  the  extremity  bj^  an  involuntary 
sphincter  muscle,  which  varies  much  in  rigiditj^  in 
different  animals  ;  often  it  is  so  lax  that  the  pressure 
of  a  small  amount  of  milk  in  the  canal  is  sufficient 
to  open  it  and  the  animal  leaks  her  milk.  In  other 
animals  it  requires  a  strong  effort  of  the  hand  to 
draw  the  milk.  When  desirable,  the  rigidity  may  be 
overcome  by  keeping  a  smooth  wooden  plug  of  suf- 
ficient size  to  moderately  dilate  the  opening  in  the 
end  of  the  teat  till  the  muscle  relaxes  sufficiently 
to  permit  easy  drawing  of  the  milk,  or  the  muscle 
may  be  partially  divided  with  the  knife  in  the 
hands  of  a  skilful  operator.  At  the  top  of  the 
teat,  or  bottom  of  the  udder,  there  is  a  small 
cavity  known  as  the  milk  cistern,  serving  to  hold 
the  milk  after  its  secretion  until  it  is  drawn. 
It    is     of    varying     capacity,    up     to     half     a     pint, 


Arrangement   of  Milk   Ducts.  5 

and  is  partially  separated  from  the  canal  of  the 
teat  by  a  more  or  less  well  -  marked  constriction 
in  the  muscular  walls  of  the  upper  part  of  the 
teat.  From  the  milk  cisterns  a  system  of  canals 
or  so-called  milk  ducts  extends  to  all  portions  of 
the  udder.  These  ducts  are  larger  near  their  open- 
ing into  the  milk  cistern,  and  diminish  in  size 
as  they  rise  through  the  udder.  They  branch  and 
anastomose  freely  in  all  directions,  and  finally  end 
in  a  group  of  small  sac -like  bodies,  the  ultimate 
follicles.  The  system  of  milk  ducts  arising  from 
each  teat  is  practically  distinct,  though  there  is 
more  or  less  communication  between  the  smaller 
ducts  in  the  upper  portions  of  the  two  quarters 
on  the  same  side  of  the  animal.  This  renders 
it  possible  to  draw  a  part  of  the  milk  secreted 
in  the  hind  quarter  from  the  forward  teat  on 
the  same  side,  and  vice  versa.  There  is  no  com- 
munication between  the  ducts  on  opposite  sides 
of  the  animal.  At  the  junctions  of  the  larger 
ducts  there  are  greater  or  smaller  enlargements, 
forming  small  cavities  or  milk  reservoirs,  which 
serve  the  same  purpose  as  the  reservoirs  at 
the  top  of  the  teat.  The  branching  points  of 
all  the  ducts,  large  and  small,  are  guarded  by 
sphincter  muscles.  These  muscles  are  connected 
with  the  abdominal  muscles  of  the  animal,  and  she 
is  able  to  more  or  less  completely  close  them  at 
will,  and  so  "hold  up"  her  milk.  It  requires  a 
strong  effort  on  the  part  of  the  animal  to  com- 
pletely  close   the    larger   ducts   in   the   lower   part   of 


6  Milk   and   Its   Products. 

the  udder ;  a  comparatively  slight  effort  is  all  that  is 
necessary  to  close  the  smaller  vessels.  Animals  vary 
greatly  both  in  the  control  they  possess  over  these 
muscles  and  in  their  disposition  to  use  it.  Very  few 
can  completely  close  the  larger  ducts,  and  very  many 
rarely  exercise  whatever  power  they  do  possess.  Sud- 
den fright,  the  presence  of  strange  persons  or  animals 
in  the  stable,  any  irregularitj'  in  the  time  or  manner 
of  feeding  or  milking,  and  slight  feverish  conditions, 
particularly  sexual  heat,  are  the  most  common  pro- 
vocatives to  holding  up  milk.  There  are  very  many 
cows  that  contract  the  habit  of  holding  up  the  milk 
upon  the  slightest  provocation,  and  if  the  habit  is 
once  formed  it  is  almost  impossible  to  cure  it,  and 
the  result  is  that  the  usefulness  of  the  animal  as 
a  milk  producer  is  largely  destroyed,  for  the  reten- 
tion of  the  milk  in  the  udder  interferes  greatly 
with  the  activity  of  secretion,  and  in  a  short  time 
permanently   lessens   it. 

The  ultimate  follicles.— The  milk  ducts,  after 
branching  and  anastomosing  in  all  dh*ections,  finally 
end  in  a  group  of  small  sac -like  bodies  known  as 
acini,  or  ultimate  follicles.  It  is  in  these  small 
bodies  that  the  secretion  of  the  milk  takes  place. 
They  are  about  l-30th  of  an  inch  in  diameter,  and 
are  found  in  groups  of  three  to  five,  with  a  com- 
mon outlet  at  the  end  of  each  branching  duct. 
In  form  and  appearance  they  present  marked 
changes  according  to  the  condition  of  the  animal. 
During  active  lactation  they  are  found  in  their 
highest    development.       When     lactation    ceases,    the 


Secretion   of  Milk.  7 

smaller  ducts  become  much  retracted,  aud  the 
follicles  shrink  in  size  and  finally  become  rudimen- 
tary, or  even  entirely  disappear,  until  under  the 
stimulus  of  a  succeeding  pregnancy,  the  whole 
gland  renews  its  activity,  and  the  ducts  and  fol- 
licles regain  their  former  size  and  appearance. 
New  ducts  and  follicles  may  also  be  formed  up  to 
about  the  fifth  or  sixth  j^ear,  and  the  power  of 
the  animal  to  secrete  milk  be  thereby  increased. 
Surrounding  the  follicles,  and  intimately  attached 
to  them,  are  capillary  blood  vessels,  both  veins  and 
arteries,  and  through  the  cells  of  the  membranes 
making  up  the  walls  of  all  these  vessels  the  fluids 
of  the  blood  freely  pass  into  the  cavity  of  the 
follicles  by  means  of  osmosis,  or  transudation. 
The  cavity  of  the  follicle  is  lined  with  epithelial 
cells,  that  during  lactation  are  filled  with  proto- 
plasm, and  are  capable  of  rapid  multiplication, 
growth,  and  degeneration,  at  the  same  time  that 
the  cell  contents  are  undergoing  rapid  and  exten- 
sive  changes. 

The  secretion  of  milk. — The  milk  is  formed  from 
the  blood,  partly  by  the  transudation  of  the  blood 
serum  directly  into  the  cavity  of  the  milk  follicle, 
and  partly  by  a  transformation  of  the  contents  of 
the  epithelial  cells  lining  the  cavity  of  the  follicle, 
which  at  this  time  are  especially  active.  The 
water  passes  directly  from  the  capillaries  into  the 
milk  follicles  and  ducts,  carrjdng  with  it  the  min- 
eral constituents  in  solution  and  a  part  of  the  al- 
bumin   of    the   blood   serum;    but   by   far    the   larger 


8 


MiJli  and  Its  Froduds. 


part  of  the  albumin  is  in  some  way  changed  dur- 
ing its  passage  from  the  capillaries,  and  appears  in 
the   cavit}^   of   the  follicle  as   the  casein   of   the    milk. 


Fig.  1.    Section  tlirougli  alveoli  of  the  mammary  glaud  of  the  dog  in  first  and 
second  stages  of  secretion.    From  Meade  Smith,  after  Heidenhain. 


When  milk  is  being  secreted,  the  lining  cells  of 
the  follicle  are  in  a  state  of  constant  activity. 
New  cells  are  constantly  being  formed  by  budding 
or  fission  (the  cell  elongates,  a  partition  forms 
across  it,  and  the  two  halves  so  divided  enlarge  to 
the  size  of  the  mother  cell,  and  there  are  two  cells 
where  but  one  existed  before),  and  older  cells  are 
as  constantly  breaking  down.  ^Yhile  this  is  going 
on,  the  cell  contents,  consisting  mainh'  of  protoplasm, 
become  changed  into  a  globule  of  fat,  and  the 
globules  so  formed  are  either  extruded  through  the 
cell  wall  into  the  cavity  of  the  follicle,  or  set  free 
by  the  breaking  down  and  reabsorption  of  the  cell 
wall.  In  all  probability  both  processes  take  place. 
Small  portions  of  the  fat  may  also  be  carried  over 
directly  from  the  blood  and  appear  in  the  milk 
without  change.       The  milk  sugar  is  probably  formed 


Incentives   to   Secretion.  9 

through  a  chemical  change  in  the  contents  of  these 
lining  cells,  since  but  minute  quantities  of  sugar 
are   found  in   the   blood. 

Incentives  to  secretion. — Maternity  is  the  prime 
incentive  to  the  secretion  of  milk.  While  there  is 
a  distinct  increase  in  the  development  of  the  mammae 
upon  attaining  pubertj^  it  is  not  until  pregnancy  is 
well  advanced  that  the  organ  attains  anywhere  near 
its  full  development,  or  that  there  is  any  activity 
in  the  true  secreting  cells.  In  the  virgin  .animal, 
and  up  to  within  a  short  time  of  parturition,  the 
cavities  and  ducts  of  the  udder  contain  a  watery 
saline  fluid,  but  true  milk  does  not  appear  until  a 
short  time  before,  and  in  some  cases  not  until  after, 
parturition.  The  immediate  stimulus  to  the  produc- 
tion of  milk  is  the  turning  of  the  blood  that  went 
to  nourish  the  foetus  from  the  arteries  of  the  uterus 
to  the  arteries  of  the  udder.  The  pressure  of  blood 
in  the  vessels  of  the  udder  stimulates  the  secreting 
cells  to  great  activity,  and  the  cells,  hitherto  dor- 
mant, begin  to  multiply  rapidly.  When  this  activity 
is  first  set  up,  the  various  processes  of  secretion  are 
more  or  less  incomplete,  so  that  the  milk  first  se- 
creted is  verj^  different  in  character  from  that  se- 
creted afterwards,  and  is  known  as  colostrum.  The 
colostrum  contains  in  the  first  place  considerably 
less  water  than  normal  milk;  in  the  second  place, 
the  transformation  of  albumin  into  casein  is  only 
partial,  so  that  colostrum  contains  large  amounts  of 
albumin;  and  finally,  when  secretion  of  milk  begins, 
the    cells    of   the   follicle  multiply   more    rapidly   than 


10  Milk    and   Its    Products. 

they  can  be  reabsorbed,  and  portions  of  partially 
broken  down  cells  break  away  from  tlie  walls  of 
the  follicle  and  appear  in  the  colostrum.  Gradually 
the  colostrum  takes  on  the  character  of  normal 
milk,  and  in  the  course  of  four  or  five  days  the 
change  is  complete.  Other  characteristics  of  colos- 
trum  are  discussed  in  detail   in  the  next  chapter. 

While  maternity  is  the  prime  cause  of  secretion, 
it  is  not  the  only  means  of  stimulation  to  the  ac- 
tivity of  the  udder,  nor  is  it  a  necessary  prerequisite 
to  the  secretion  of  milk.  The  regular  removal 
of  the  saline  fluid  in  the  gland  of  the  virgin 
animal,  or  even  the  stimulation  of  the  organ  by  the 
friction  of  the  hand  or  the  suckling  of  a  calf,  may 
be  sufftcient  to  cause  the  secretion  of  milk  of  nor- 
mal character  in  considerable  quantities.  In  the 
same  way  and  under  the  same  exciting  causes,  other 
glands  of  the  body,  notably  the  l^^llphatics  in  the 
arm  pits  and  the  rudimentary  mamma)  of  males, 
have  been  known  to  secrete  a  fluid  resembling  milk 
in   all   essential   characteristics. 

Amount  and  duration  of  flou\ — With  wild  ani- 
mals in  a  state  of  nature,  the  milk  is  secreted  only 
in  amount  sufficient  for  the  needs  of  the  young 
animal,  and  only  until  the  young  is  sufficiently  de- 
veloped to  secure  its  food  independently  of  the 
mother.  Under  the  influence  of  domestication  the 
cow  has  been  brought  to  increase  her  flow  of  milk 
many  fold,  and  the  time  during  which  it  is  se- 
creted has  been  lengthened  until  it  is  almost,  and 
indeed   is,  in   some   cases   quite   continuous.       A   dis- 


Dependence   upon    Circulation   of  Blood.  11 

cussion  of  the  agencies  by  means  of  which  this 
most  important  resnlt  has  been  brought  about 
would  open  up  the  whole  question  of  the  selection, 
breeding  and  training  of  cows,  as  well  as  every- 
thing pertaining  to  the  science  of  foods  and  feed- 
ing, which  is  not  here  possible.  There  are,  how- 
ever, some  physiological  conditions  affecting  the 
secretion   of   milk   that   may   be   mentioned. 

Milk  is  secreted  from  the  blood.  The  amount 
of  milk  secreted  will,  therefore,  depend  upon  the 
amount  of  blood  passing  through  the  udder,  and 
this,  in  turn,  will  depend  upon  the  number  and 
size  of  the  blood  vessels,  not  only  in  the  udder  it- 
self, but  leading  to  it  and  away  from  it,  the  vigor 
of  the  circulation,  the  supply  of  food  to  the  ani- 
mal, and  her  capacity  to  eat,  digest  and  assimilate 
it  and  turn  it  into  blood.  From  or  shortly  after 
parturition,  there  is  a  constant  tendency  of  the 
blood  vessels  in  the  udder  to  shrink  in  size,  and 
consequently  a  Constantly  diminishing  flow  of  milk. 
When  the  period  of  lactation  advances  at  the  same 
time  that  the  pastures  are  growing  more  scanty 
and  less  succulent,  this  diminution  is  fairly  regular 
and  constant,  especially  after  from  three  to  five 
months  of  the  period  of  lactation  have  passed.  This 
tendency  to  shrinkage  in  the  size  of  the  blood 
vessels  of  the  udder  may  be  held  in  check  in  great 
measure  by  an  abundant  supply  of  nutritious  food, 
particularly  if  it  is  of  a  succulent  character,  and 
it  is  not  at  all  uncommon  to  find  cows  secreting 
milk   in  regular   amount,  or  "holding   out,''  for   eight 


12  Milk  and  Its  Products. 

or  ten  months.  But  in  this  respect  the  individ- 
uality of  the  animal  plan's  an  important  part,  so 
that  wide  variations  are  seen  in  different  individ- 
uals under  the  same  conditions  of  food  and  care. 
After  a  shrinkage  in  the  flow  has  once  taken  place, 
it  is  extremely  difiicult  to  again  increase  it  by 
increased   food   until    after   another   calving. 

Effect  of  succeeding  pregnancy. — The  effect  of  the 
animal  again  becoming  pregnant  is  to  decrease  the 
flow  of  milk.  The  cause  of  this  decrease  seems, 
in  many  cases,  to  be  two-fold:  First,  a  sympa- 
thetic effect,  following  immediately  upon  conception, 
and  secondly,  a  shrinkage  due  to  a  turning  away  of 
a  part  of  the  blood  from  the  udder  to  nourish  the 
growing  foetus.  This  shrinkage  does  not  become 
marked  until  the  fourth  or  fifth  month  of  preg- 
nancy. In  this  respect,  as  in  their  power  to  "hold 
out,"  individual  animals  show  the  widest  variation. 
With  very  many  the  effect  of  becoming  again  preg- 
nant is  so  slight  as  to  be  scarcely  noticeable  ;  with 
others  it  is  so  gi-eat  as  to  materially  interfere  with 
the   usefulness    of   the   animal. 

Incomplete  removal  of  mill-. — One  of  the  most 
important  means  of  checking  the  secretion  of  milk 
lies  in  the  incomplete  removal  of  milk  already  se- 
creted. We  have  already  seen  that  the  removal 
of  the  saline  fluid  from  the  ducts  of  the  inactive 
gland  is  an  efficient  stimulus  to  secretion.  So,  too, 
the  presence  of  milk  in  the  ducts  acts  as  a  check 
to  further  secretion.  Further  than  that,  it  not 
onlj'   checks    secretion  but   is  an  actual  ii'ritant,  suffi- 


Regularity   of  Milking.  13 

cient  in  many  instances  to  give  rise  to  inflammations 
of  a  serious  character.  Clean  milking  is  one  of 
the  most  important  aids  in  keeping-  up  and  pro- 
longing  the   flow   of   milk. 

Regularity  and  frequency  of  milhing. — While  the 
process  of  milk  secretion  is  a  continuous  one,  it  is 
not  entii'ely  uniform.  There  is  reason  to  believe 
that  the  secretion  is  considerably  more  rapid  while 
the  operation  of  milking  is  going  on,  and  that  a  con- 
siderable portion  of  the  whole  amount  is  then  secreted. 
On  the  other  hand,  the  distension  of  the  milk  ducts 
and  reservoirs  by  milk  already  secreted  acts  as  more 
or  less  of  a  check  upon  the  activity  of  the  follicles, 
and  so  lessens  the  rapidity  of  secretion.  While  for 
these  reasons  it  would  be  inferred  that  frequent 
milking  would  lead  to  increased  secretion,  the  limits 
of  such  increased  secretion  are'  moderate,  and  beyond 
a  certain  point  no  increased  flow  of  milk  is  secured 
by  increasing  the  frequency  of  the  milking  periods. 
In  all  cases  where  the  udder  becomes  unduly  dis- 
tended with  milk  between  periods,  an  increased  flow 
will  be  secured  by  milking  oftener.  The  common 
practice  is  to  milk  twice  in  the  twenty -four  hours, 
and  the  nearer  the  time  can  be  divided  into  equal  pe- 
riods the  more  uniform  will  be  the  secretion.  Where 
more  frequent  milking  is  practiced  the  same  principle 
will  hold.  Not  only  is  regularity  in  the  period  from 
morning  to  night  of  importance,  but  regularity  in 
the  time  of  milking  from  day  to  day  is  equally  so. 
A  difference  of  an  hour  in  the  time  of  milking  will 
frequently   make    a   difference   of    10   per   cent    in  the 


14  Milk   and   Its   Products. 

amount  secreted,  and  where  these  irregularities  are 
frequent,  will  soon  result  in  a  considerably  diminished 
flow.  The  amount  of  milk  given  is  also  considerably 
affected  by  the  way  in  which  the  milk  is  di-awn. 
In  general,  it  may  be  said  that  rapid  milking  is 'con- 
ducive to  a  large  flow.  In  any  event,  the  milk 
should  be  drawn  so  that  no  discomfort  is  caused 
the  animal,  and  in  this  respect  there  is  great  dif- 
ference in  milkers.  A  rapid,  uniform  stroke,  with 
a  firm  touch  on  the  teat,  and  a  stroking  motion  to 
the  lower  part  of  the  udder,  gives  the  best  results. 
Babcock  has  found  that  certain  milkers  uniformly  get 
not  only  more  but  richer  milk  from  the  same  cow. 
Control  of  the  animal  over  secretion. — The  secre- 
tion of  milk  is  involuntary.  The  animal  can  no 
more  control  it  than  it  can  control  the  respiration 
or  the  circulation  of  the  blood.  Yet  there  are 
numerous  conditions  of  the  animal  that  have  a 
more  or  less  direct  effect  upon  the  secretion  of  milk. 
These  conditions  have  not  only  to  do  with  the  physi- 
cal condition  of  the  animal — as  the  supply  of  food, 
the  circulation  of  the  blood,  extremes  of  temperature, 
etc. — but  extend  in  large  measure  to  the  nervous 
organization  and  condition  of  the  animal.  We  have 
already  seen  that  the  animal  may  by  an  exercise  of 
will  more  or  less  completely  control  the  withdrawal 
of  milk  already  secreted ;  so,  too,  there  are  nervous 
conditions  that  have  a  great  effect  upon  the  actual 
secretion.  Sudden  fright,  an  unfamiliar  milker  or 
attendant,  unusual  excitement,  sexual  excitement,  or 
the   presence   of   an   animal   in   heat   in    the  herd,  an 


Physical    Condition   of  Animal.  15 

unusual  amount  of  exercise,  or  any  one  of  many 
other  causes,  may  be  sufficient  to  decrease  the  secre- 
tion of  milk  one -half  in  any  one  day.  The  effect 
of  such  disturbances  is  usually  quickly  overcome,  but 
their  frequent  recurrence  leads  to  a  permanent  diminu- 
tion of  the  secretion.  The  nervous  organization 
of  the  animal  is  a  most  important  factor  in  deter- 
mining the  effect  of  these  various  disturbing  influ- 
ences. Many  of  the  animals  in  which  the  powers  of 
digestion,  nutrition  and  secretion  are  most  highly  de- 
veloped are  possessed  also  of  a  highly  developed  and 
sensitive  nervous  system,  and  hence  are  easily  affected 
by  any  disturbing  condition.  With  all  such  animals 
it  is  of  the  utmost  importance  that  every  condition 
surrounding  the  animal  should  be  as  regular  and 
uniform  as  possible.  Other  animals  of  equal  capacity 
show  a  remarkably  quiet  and  phlegmatic  nervous 
temperament,  and  are  consequently  slightly  or  not  at 
all  affected  by  such  disturbing  influences.  Such  an- 
imals are  of  great  value  to  the  milk  producer,  for 
with  the  utmost  care  and  regularity  there  are  always 
disturbing  influences  beyond  the  control  of  the 
dairyman. 


CHAPTER  Ilo 

COMPOSITION   OF  MILE. 

The  constituents  of  milk  are  numerous  and  of 
diverse  character,  but  may  be  easily  classified  into  a 
few  well  marked  groups  as  follows:  (a)  water,  (b) 
fats,  (c)  substances  containing  nitrogen  (albumi- 
noids), (d)  sugar,  (e)  ash.  Excepting  the  water,  they 
are  collectively  known  as  milk  solids.  The  solids 
exist  partly  in  solution,  partly  in  semi -solution,  and 
partly  in  suspension  in  the  water.  Milk  from  the 
various  classes  of  animals  has  the  same  general 
constitution  and  properties,  and  varies  only  in  the 
relative  proportions  of  the  various  proximate  con- 
stituents. Cow's  milk  is  typical  of  all  milks,  and  as 
it  is  the  only  milk  used  in  processes  of  manufac- 
ture in  the  United  States,  all  of  our  discussions 
have  reference  to  it  alone.  In  various  other  coun- 
tries milk  from  the  goat,  ass,  mare  and  ewe  is  con- 
siderably used,  not  only  as  food  but  for  the  man- 
ufacture of  various  products.  Indeed  the  peculiar- 
ities of  some  of  these  is  supposed  to  be  largely  due 
to  their  having  been  made  from  the  milk  of  ani- 
mals other  than  the  cow.  Koumiss,  made  from 
mare's  milk  in  Arabia,  and  Roquefort  cheese,  made 
largely  from  ewe's  milk,  are  noteworthy  examples. 

(16) 


Percentage    Composition.  17 

All  of  the  milk  constituents  are  more  or  less  va- 
riable in  quantity,  and  manj-  of  them  vary  widely; 
hence  it  is  not  possible  to  make  a  statement  of  the 
average  percentage  composition  of  milk  that  will  give 
more  than  a  general  idea  of  its  composition.  The 
following  are  taken  from  recent  authorities  in  the 
various  countries: 


American. 

English. 

German. 

French. 

(Babcock.) 

(Oliver.) 

(Fleischmann.) 

(Cornevin.) 

Water     .  . 

.   .    87.17 

87.60 

Sl.lb 

87.75 

Fat  .   .   . 

•    .      3  69 

3  25 

-       3.40 
2.80 

3.30 
3.00 

Casein    . 

.   .      3.02 

3.40 

Albumin 

.   .        .53 

.45 

.70 

Sugar .   .   . 

.   .      4.88 

4.55 

4.60 

4.80 

Ash.   .   .   . 

.    .        .71 

.75 

.75 

.75 

100.00         100.00        100.00         99.60 

The  following,  from  Koenig,  shows  the  range  of 
variation  of  the  several  constituents  in  nearly  800 
analyses   collected   from   all   parts   of   the   world: 

Maximum.  Minimum. 

Water       90.69  80.32 

Fat 6.47  1.67 

Casein 4.23  1,79 

Albumin 1.44  .25 

Sugar 6.03  2.11 

Ash 1.21  .35 

While  the  range  of  variation  shown  above  is 
considerable,  some  of  the  constituents,  notably  the 
fat,  may  show  even  greater  ranges  in  milk  secreted 
by  normal,  healthy  cows.  It  is  probable  that  the 
minimum  of  Koenig  is  seldom  exceeded,  but  as  high 
as  10  per  cent  of  fat  has  been  found  in  the  milk 
of  single  cows  giving  a  very  small  quantity.  Bab- 
cock  states   that   no    analysis    showing    more    than    9 

B 


18  Milk   and   Its   Products. 

per  cent  of  fat  is  recorded  from  any  cow  giving  as 
much  as  15  pounds  of  milk  per  day.  Any  analj'sis 
above  7  per  cent  is  extremely  rare,  and  should  be 
regarded  with  suspicion  unless  well  authenticated. 
The  mixed  milk  of  herds  seldom  falls  below  3  per 
cent  of  fat  and  rarely  rises  above  5.5  per  cent. 

Colostrum. — The  first  milk  secreted  by  the  animal 
after  parturition  is  quite  distinct  in  composition  and 
physical  properties  from  that  produced  after  the 
secretion  has  become  well  established.  Such  milk 
is  called  colostrum,  and  is  ordinarily  considered 
unfit  for  consumption  or  manufacture.  Colostrum 
differs  from  normal  milk  chiefly  in  its  less  proportion 
of  water  and  sugar,  in  the  much  greater  proportion 
of  albumin  and  ash,  in  the  extremely  variable  amount 
of  fat,  and  in  the  presence  of  small  organized  bodies 
known  as  colostrum  corpuscles,  which  are  probably 
debris  of  the  cell  structure  of  the  gland.  The  follow- 
ing analyses  from  Richmond  after  Vaudin  show  the 
extremely  variable   composition  of  colostrum: 

No.  1.  No.  2. 

Water 72.39  75.51 

Fat .      1.30  6.152 

Sugar 1.52  2.17 

Px'oteids  (casein,  albumin,  etc.) 23.70  14.91 

Ash 1.09  1.09 

100.00  100.00 

The  percentage  of  albumin  in  colostrum  is  so 
great  that  it  will  cause  the  whole  mass  of  milk  to 
thicken  upon  boiling,  and  this  is  ordinarily  consid- 
ered a  sufficient  test  for  determining  the  suitability 
pf   the  milk  for  consumption  or  manufacture,     With- 


Specific    Gravity   of  Milk.  19 

in  four  or  five  days  after  calving,  the  miik  loses  its 
colostrum  character  and  takes  on  its  normal  condi- 
tion. This  change  is  a  gradual  and  progressive  one, 
and  is  more  or  less  dependent  upon  the  physical, 
condition  of  the  animal.  When  the  cow  is  feverish, 
or  when  there  is  local  inflammation  in  the  udder, 
the  colostrum  character  of  the  milk  is  retained 
for  a  longer  period  than  otherwise.  The  amount 
of  coloring  matter  present  is  also  considerably 
greater  in  colostrum  than  in  normal  milk,  and  the 
percentage  of  fat  varies  very  widely.  Usually  the 
percentage  of  fat  is  less  in  the  colostrum  than  in 
the  normal  milk  from  the  same  cow,  although  oc- 
casions are  not  infrequent  where  more  fat  is  found 
in  the  milk  immediately  after  calving  than  at  any 
other   time   in   the  whole   period   of    lactation. 

Specific  gravity  of  milk. —  Some  of  the  solids  of 
milk  are  heavier  than  water  and  some  of  them  lighter, 
milk  as  a  whole  having  a  specific  gravity  somewhat 
greater  than  water.  The  variation  in  the  specific 
gravity  is  considerable,  the  range  usually  given  being 
from  1.029  to  1.035  at  60°  F.,  the  average  being 
about  1.032.  In  general,  the  effect  of  an  increase 
in  the  solids  of  the  milk  is  to  increase  its  specific 
gravity,  though  in  milk  extremely  rich  in  fats  (6 
per  cent  or  above)  the  specific  gravity  is  lessened. 
Formerly,  more  than  at  present,  it  was  the  custom 
to  estimate  the  quality  of  the  milk  by  determining 
its  specific  gravity,  but  as  soon  as  it  became  known 
that  the  specific  gravity  depended  not  so  much  upon 
the   amount    as   upon   the   character   of    the   solids,   a 


20  Milk   and   Its   Products. 

determination  of  the  specific  gravity  became  of  little 
value.  Unscrupulous  dairymen  soon  learned  that 
water  could  be  added  to  milk  and  fat  or  cream 
taken  from  it  in  such  proportions  that  the  specific 
gravity  would  remain  the  same  as  that  of  normal 
milk. 

The  fats.— The  fat  of  milk,  or  butter  fat,  as  it 
is  often  called,  is  a  mixture  of  a  considerable  number 
of  separate  and  distinct  fats,  no  less  than  six  or 
eight  being  normal  to  milk,  and  a  considerable  fur- 
ther number  may  be  present  under  various  conditions. 
The  fats  in  milk  are  of  two  kinds,  volatile  and  non- 
volatile. To  the  former  class  belong  the  various 
normal  essential  oils  that  give  to  milk  and  butter 
their  characteristic  odors  and  flavors,  and  in  addition 
to  these  normal  fats  there  may  be  a  large  number 
of  volatile  oils  that  are  present  in  the  food  of  the 
cow,  and  that  impart  to  the  milk  the  characteristic 
flavors  of  such  foods. 

The  volatile  fats.— The  volatile  fats  make  up  only 
a  small  part  of  the  total  milk  fat ;  in  general,  prob- 
ably about  15  per  cent  of  the  whole.  The  chief 
normal  volatile  fats  are  butyrin,  caprin,  caproin, 
caprilin  and  laurin.  Of  these,  butyrin  is  in  much 
the  largest  proportion  and  of  much  the  greatest  im- 
portance. It  is  the  chief  volatile  fat  of  milk  and 
butter,  and  to  it  are  due  in  large  part  the  character- 
istic flavors  and  aromas  of  milk  and  butter.  ButjTin 
readily  decomposes,  forming  butyric  acid,  which  is  the 
chief  element  in  the  rancid  or  "  frowy "  taste  that 
butter  acquires  upon  long  standing. 


Effect   of  Strong -flavored   Foods.  21 

The  volatile  fats  that  are  derived  directly  from 
the  food  may  give  either  desirable  or  undesirable 
flavors  to  the  milk.  Thus  we  esteem  the  character- 
istic flavors  due  to  the  grasses,  clover  and  like  fodder ; 
on  the  other  hand,  the  stronger  flavors  of  garlic, 
onions,  turnips,  cabbage,  etc.,  give  to  the  milk  an 
undesirable  character. 

The  presence  of  these  undesirable  flavors  in  milk 
is  often  a  source  of  a  good  deal  of  annoyance,  but 
with  proper  precautions  the  bad  results  coming  from 
them  may  be  greatly  lessened,  and  in  many  cases 
entirely  obviated.  Since  all  of  these  flavoring  oils  are 
volatile,  they  easily  pass  through  all  the  tissues  of 
the  animal,  and  in  a  comparatively  short  time  pass 
off  through  the  various  excretor}'  channels.  We  shall 
find  them  present  in  the  greatest  amount  not  only 
in  the  milk,  but  in  all  the  tissues  of  the  animal, 
during  the  time  that  the  fodder  containing  them  is 
undergoing  digestion,  and  by  the  time  the  digestion 
is  completed  the  volatile  products  will  have  almost 
entirely  passed  away.  If,  therefore,  sufficient  care 
is  taken  to  so  time  the  feeding  and  milking  that  the 
milk  shall  be  drawn  not  less  than  ten  or  twelve 
hours  after  the  undesirable  fodder  has  been  eaten, 
there  will  be  slight  danger  of  contamination  of  the 
milk  by  it.  Whereas,  if  milking  occurs  within  three 
or  four  hours  after  feeding,  the  milk  will  be 
strongly  impregnated  with  the  undesirable  flavor. 
Taking  advantage  of  this,  and  feeding  cows  immedi- 
ately before  or  immediately  after  milking,  dairymen 
are  often  enabled   to  feed   large  quantities  of   turnips, 


22  Milk    and   Its    Products. 

and  even  onions,  ^Yithont  danger  of  contamination  of 
the  milk.  The  presence  of  wild  garlic  and  wild 
onions  in  pastures  is  a  source  of  bad  flavor  in  the 
milk  in  a  considerable  portion  of  the  country.  Where 
this  is  the  case  it  is,  of  course,  more  difficult  to 
overcome  the  bad  flavor ;  but  bj'  allowing  the  cows 
to  pasture  for  a  comparatively  short  time  only  im- 
mediately after  milking,  and  keeping  them  up  and 
giving  them  some  dry  food  for  three  or  four  hours 
before  milking,  there  will  be  a  great  deal  less  an- 
noyance  from    this    source. 

The  non-volatile  fats. — The  non-volatile  fats  make 
up  about  85  per  cent  of  the  whole  amount  of  fat, 
and  consist  of  a  more  or  less  uncertain  and  variable 
mixture  of  several  fats,  of  which  olein  and  palmitin 
make  np  the  chief  part.  They  are  glycerides  of  the 
corresponding  fatty  acids— oleic,  palmitic,  stearic,  myr- 
istic,  etc.,  and  differ  from  one  another  chiefly  in 
their  hardness  or  melting  point.  Olein  is  liquid  at 
ordinarj'  temperatures ;  palmitin  and  the  others  are 
solid.  Olein  melts  at  about  41°  F.,  the  hard  fats  at 
various  temperatures  from  130°  to  150°  F.  The 
mixture  of  the  whole,  as  we  find  them  in  ordinary 
butter,  melts  at  from  92°  to  96°  F.  The  hardness 
or  softness  of  different  butters,  depending  largely 
upon  varying  proportions  of  olein.  Considerable  doubt 
exists  as  to  the  relative  proportions  of  the  various 
fats  and  fatty  acids.  Browne*  gives  the  following 
percentages  of  volatile  and  non- volatile  fatty  acids: 


*Jour.  Am.  Chem.  Soc.  21,  823. 


The   Non- volatile    Fats  23 

Oleic 33.95 

Palmitic 40.51 

Myristic .        10.44 

Stearic 1.91 

Diosystearic 1.04 

Butyric 6.23 

Laurie 2.73 

Caproij 2.32 

Caprylic 53 

Capric 34 

100.00 

It  is  asserted  that  the  coloring  matter  of  the 
fat  is  most  intimately  associated  with  the  palmitin. 
The  fat  exists  in  the  milk  in  the  form  of  an  emul- 
sion of  extremelj^  small  globules,  varying  in  size 
from  — 5^)0-  to  25"ooo'  of  an  inch  in  diameter.  These 
globules  are  not  surrounded  by  pellicles,  or  so- 
called  skins,  as  was  formerly  thought,  but  main- 
tain their  form  by  reason  of  the  surface  tension  of 
the  liquid  fat,  and  also  to  some  extent  because  of 
a  layer  of  more  or  less  condensed  casein  that  im- 
mediately surrounds  them.  The  permanency  of  the 
emulsion  is  further  increased  by  the  viscous  nature 
of  the  milk  serum,  due  to  the  presence  of  sugar 
and  other  solids  in  solution. 

The  albuminoids. — The  casein  is  the  chief  albu- 
minoid of  milk,  although  there  is  always  present  a 
small  amount  of  albumin,  and,  according  to  some 
authorities,  of  fibrin.  Casein  is  of  prime  impor- 
tance in  the  manufacture  of  cheese,  and  it  is  the 
chief  constituent  that  goes  to  form  tissue  when  milk 
is  used  as  a  food. 

There   is   a    good   deal   of    doubt   as   to   the   form 


24  Milk    and   Its   Products. 

in  which  the  casein  exists.  Formerly  it  was  sup- 
posed that  the  casein  is  in  solution.  This  idea 
was  brought  about  by  the  fact  that  it  is  impossible 
to  filter  the  casein  from  the  milk,  even  though  it 
is  passed  through  several  thicknesses  of  fine  paper. 
Later,  though,  it  was  found  that  when  milk  is 
passed  through  a  fine  porcelain  filter  a  certain  part 
is  removed,  and  it  was  then  supposed  that  there 
were  two  forms  of  casein,  one  of  which  was  in 
solution  and  the  other  in  suspension  in  very  fine 
particles  of  a  colloidal  or  gummy  character.  Still 
later  investigations  have  shown  that  in  all  proba- 
bility a  large  part  of  the  casein  is  in  this  extremely 
fine  colloidal  state.  When  milk  is  subjected  to 
the  action  of  weak  organic  or  mineral  acids,  to 
rennet  or  to  certain  vegetable  substances,  the  casein 
is  precipitated  in  a  flocculent  mass.  Casein  is  not 
acted  upon  by  heat.  The  albumin  of  the  milk  is 
in  all  respects  similar  to  blood  albumin.  It  is 
rendered  insoluble  by  a  heat  of  about  180°  F.,  but 
it  is  not  acted  upon  by  weak  acids  or  rennet,  and 
in  this  way  it  is  chiefly  distinguished  from  the 
casein.  The  fibrin  of  milk,  if  present,  is  in  ex- 
tremely minute  quantities.  It  is  supposed  to  be 
the  same  as  blood  fibrin,  and  coagulates  upon  ex- 
posure to  the  air,  but  is  never  present  in  sufficient 
quantity  to  form  a  clot,  as  in  the  case  of  blood. 
Its  coagulation  is  hindered  by  a  reduction  of  tem- 
perature, and  it  has  been  supposed  that  when  it  does 
coagulate  it  forms  a  sort  of  network  of  threads 
through    the  mass  of    milk. 


Milk   Sugar  and   Ash  25 

The  sugar. —  Milk  sugar,  otherwise  called  lactose, 
exists  in  solution  in  the  milk  serum.  It  has  the 
same  chemical  composition  as  cane  sugar :  that  is, 
C12H22O11 -|- H2O.  It  crystallizes  with  considerable 
difficulty,  and  has  very  much  less  sweetening  power 
than  ordinary  sugar.  Under  the  influence  of  vari- 
ous ferments  it  readily  undergoes  decomposition, 
each  molecule  of  sugar  breaking  up  into  four  mol- 
ecules of  lactic  acid.  This  change  begins  in  the 
milk  almost  immediately  after  it  is  drawn,  and  con- 
tinues until  about  .8  of  1  per  cent  of  lactic  acid 
is  formed.  The  presence  of  lactic  acid  in  this 
amount  acts  as  a  check  upon  the  growth  of  the 
ferments,  and  prevents  the  further  formation  of 
lactic  acid,  unless  the  acid  is  neutralized  with  an 
alkali,  when  the  fermentation  proceeds  as  before. 
Milk  sugar  does  not  readily  undergo  alcoholic  fer- 
mentation, but  by  the  action  of  yeast  and  some 
other  ferments  the  lactose  is  "inverted,"  or  changed 
to  dextrose  and  a  peculiar  substance  known  as  ga- 
lactose, and  these  readily  change  to  alcohol  under 
the  influence  of  the  proper  ferments. 

The  ash. — The  ash  is  the  smallest  and  least 
variable  constituent  of  the  milk.  It  is  composed 
chiefly  of  the  phosphates  of  lime  and  potash,  the 
chlorides  of  potash  and  soda,  with  small  amounts 
of  phosphate  of  iron  and  magnesia.  Most  of  the 
salts  are  in  solution.  It  seems  probable  that  at 
least  a  part  of  the  phosphate  of  lime  is  ordinarily 
in  insoluble  form,  suspended  in  the  milk  in  very 
fine    particles    in    connection    with    the    casein.     The 


26  MilJc    and    Its    Products. 

chloride  of  potash  is  largely  in  excess  of  the 
chloride  of  soda.  This  is  exactly  opposite  to  the 
proportions  of  these  two  salts  in  the  blood. 

Other  constituents. —  Besides  the  constituents  enu- 
merated above,  several  other  compounds  are  more  or 
less  normally  present  in  milk  in  minute  quan- 
tities. 

A  small  amount  of  citric  acid  is  said  to  be  a 
normal  constituent  of  milk. 

A  peculiar  substance  called  lactochrome  is  also 
a  normal  constituent  of  milk,  and  gives  to  it  its 
characteristic  color.  This  has  been  already  men- 
tioned in  connection  with  the  palmitin.  The  amount 
of  lactochrome  present  varies  under  many  condi- 
tions, notably  the  breed  of  the  animal  and  the 
character  of  the  food.  Whatever  other  conditions 
may  prevail,  the  milk  is  always  of  a  higher  color 
where  the  animals  are  fed  on  fresh  green  forage. 
This  has  led  to  the  idea  that  the  color  of  the 
milk  is  in  some  way  connected  with  the  condition 
of  the  chlorophyl  or  green  coloring  matter  of  the 
plant.  Careno*  has  suggested  that  as  the  chloro- 
phyl undergoes  a  change  when  the  plant  is  dried, 
the  digestive  organs  of  the  animal  will  have  a 
different  effect  upon  it,  and  so  account  for  the 
difference    in    color   in    the   milk. 

An  albuminoid  called  lactoprotein  has  also  been 
described  in  milk. 

Urea  to  the  extent  of  .001  of  1  per  cent  may 
also  be  regarded  as  a  normal  constituent  of   milk. 


*  Milch  Zeitung,  vol.  xxiv.  387. 


Variations   in    Quality.  27 

Variations  in  quality  of  milk. —  We  have  already 
seen  that  the  amount  of  milk  secreted  may  vary 
greatly  under  the  influence  of  a  large  number  of 
varying  conditions.  So,  too,  we  find  that  there 
are  a  large  number  of  conditions  that  affect  the 
quality  of  the  milk,  meaning  thereby  the  relative 
proportion  of  the  various  constituents,  and  particu- 
larly the  proportion  of  fat  to  other  constituents. 
Some  of  these  changes  are  regular  and  progressive 
during  the  period  of  lactation.  Others  are  due  to 
definite  causes,  and  still  others  occur  from  time  to 
time  to  which  we  have  as  yet  been  unable  to 
ascribe  any  definite  cause.  After  about  the  third 
or  fourth  week  of  lactation  the  percentage  of  fat 
in  the  milk  remains  nearly  constant  until  the  seventh 
or  eighth  month,  or  until  the  quantity  of  milk  begins 
to  rapidly  diminish  ;  but  while  the  percentage  of  fat 
does  not  markedly  change,  the  character  of  the  fat 
undergoes  several  marked  and  characteristic  changes. 
The  butter  globules  are  largest  in  size  early  in  the 
X)eriod  of  lactation,  and  constantly  diminish  as  lac- 
tation progresses,  at  the  same  time  that  they  in- 
crease in  number,  so  that  the  total  amount  of  fat 
is  not  greatly  changed.  Early  in  the  period  of  lac- 
tation there  is  a  larger  proportion  of  olein.  In 
some  cases  it  may  amount  to  50  per  cent  of  the 
total  fat.  As  the  lactation  progresses  the  propor- 
tion of  olein  decreases  and  stearin  and  palmitin  in- 
creases, until  the  proportion  of  olein  may  fall  as  low 
as  20  per  cent.  This  change  is  more  marked  when 
the   animal   changes   from   fresh   to   dry   food,  as   the 


28  Milk   and    Its   Products. 

period  of  lactation  progresses.  The  hardening  of 
the  fat  and  the  shrinking  in  the  size  of  the  glob- 
ules are  also  more  marked  when  the  animal  again 
becomes  pregnant.  In  the  case  of  cows  that  are 
milked  for  a  prolonged  period,  as  sometimes  hap- 
pens with  farrow  and  spaj-ed  cows,  the  milk  often 
becomes  abnormally  rich,  not  only  in  fat,  but  in 
casein ;  and  in  such  cases  the  fat  is  usually  made 
up   of   very   minute    globules. 

It  is  usually  observed  that  milks  drawn  at 
night  and  morning  differ  quite  widely  in  the  per- 
centage of  fat.  This  is  not  because  there  is  any 
difference  in  the  milk  secreted  by  night  or  by  day, 
although  when  cows  lie  still  there  is  a  larger  per- 
centage of  water  and  a  correspondingly  less  per- 
centage of  solids  in  the  milk.  The  difference  in 
the  milk  drawn  at  morning  and  evening  is  due  to 
the  unequal  time  that  elapses  between  the  periods. 
In  general,  the  milk  is  richest  in  fat  that  is  drawn 
after  the  shortest  period,  and  this  has  been  shown 
to  be  the  case  where  cows  have  been  milked  three 
or  four  and  even  five  times  per  day.  It  is, 
however,  not  an  invariable  rule  that  the  milk  is 
richest  succeeding  the  shortest  period.  Not  infre- 
quently it  has  been  found  that  the  milk  is  richer 
after  the  longer  period.  In  a  series  of  observa- 
tions made  by  the  writer  upon  12  cows,  ex- 
tending over  221  days,  in  72  cases  the  percentage 
of  fat  was  greater  in  the  morning  ;  in  114  cases 
it  was  greater  in  the  evening,  and  in  35  cases 
there   was   a   difference   of    .1   of    1    per   cent   or   less 


First   and   Last   Milk   Braivn.  29 

between  the  morning  and  the  evening  milk.  In  this 
instance  the  period  from  evening  to  morning  was 
about  two  hours  longer.  The  amount  of  variation 
that  may  occur  between  the  morning  and  evening  milk 
is  often  very  considerable.  In  the  great  majority 
of  cases  it  is  not  more  than  .5  of  1  per  cent, 
but  variations  so  great  as  2  or  2.5  per  cent  be- 
tween the  milk  of  one  morning  and  that  of  the 
preceding  or  following  evening  have  frequently 
been  noticed.  It  is  probable  that  a  part  of  this 
variation  may  be  explained  by  the  action  of  the 
lymphatics  of  the  udder  in  reabsorbing  a  part  of 
the  fat  when  the  milk  remains  for  a  long  time 
in    the    vessels   of    the   udder. 

There  is  also  a  considerable  variation  in  the 
milk  from  day  to  day.  This  is  usually  not  so 
great  as  between  the  morning  and  evening  milking, 
but  it  not  infrequently  amounts  to  1  per  cent. 
Such  daily  variations  may  be  ascribed  to  changes 
in  the  climate  or  other  environment  of  the  cows, — 
the  effect  of  storms,  the  effect  of  change  of  food, 
the  effect  of  slight  indispositions,  etc.;  but  there 
are  numerous  conditions  not  usually  or  readily 
recognized  by  the  owner  that  affect  the  composition 
of  the  milk.  It  has  been  noted  in  many  instances 
that  the  normal  effect  of  a  slight  febrile  condition 
of  the  animal  is  to  largely  increase  the  percentage 
of  fat  and  albumin.  If  the  febrile  condition  con- 
tinues, and  particularly  if  it  grows  more  severe, 
the  fat  then  falls  as  quickly  as  it  had  risen,  and 
to   a   correspondingly   lower   point. 


30  Milk   and    Its   Products. 

The  variation  in  the  percentage  of  fat  in  the 
milk  first  and  last  drawn  is  very  great.  The  first 
milk  drawn  is  much  the  poorer  in  fat.  Differ- 
ences so  wide  as  1  and  10  per  cent  of  fat  in 
the  first  and  last  few  pints  have  not  infrequently 
been  noticed.  This  is  due  in  large  measure  to  the 
fact  that  the  larger  globules  of  fat,  being  of 
nearly  the  same  size  as  the  smaller  milk  ducts, 
pass  along  these  vessels  less  readily  than  the  more 
fluid  portions  of  the  milk,  and  are  only  drawn 
out  with  the  last  milk  drawn.  The  milk  first 
drawn  has  been  in  the  milk  cisterns  and  larger 
vessels  for  a  considerable  period  of  time,  and  so 
has  been  subject  to  the  reabsorptive  action  of  the 
lymphatics  for  a  longer  time,  which  also  would 
tend    to    make    it    poorer    in    fat. 

The  food  also  has  a  considerable  influence  upon 
the  quality  of  the  milk,  although  the  quantity  of 
the  milk  is  more  easily  affected  by  changes  in  the 
amount  and  character  of  the  food  than  is  quality. 
In  fact,  with  cows  kept  under  favorable  conditions, 
with  an  abundant  supply  of  food,  it  is  hardly 
possible  to  increase  the  proportion  of  fat  to  other 
solids  by  a  change  in  the  food.  On  the  other  hand, 
while  the  amount  of  the  various  constituents  of 
the  milk  is  not  easily  affected  by  the  food,  the 
quality  of  the  constituents  themselves  may  be 
considerably  influenced,  notably  in  the  case  of  the 
fat.  Certain  foods  have  a  marked  influence  upon 
the  character  of  the  milk  fat.  Thus  linseed  meal, 
gluten    meal    and    certain   other    foods    make   a   soft, 


Relation   of  Fat   to    Casein  31 

oily  fat,  while  cotton -seed  meal,  the  seeds  of  the 
various  legumes  and  wheat  bran  make  a  hard  fat. 
Constituents  other  than  the  fat  are  not  so  readily 
affected    in   this   way. 

Of  the  constituents  of  milk,  the  ash  and  the 
sugar  are  the  least  variable,  the  fat  and  albumin 
the  most  variable,  while  the  casein  usually  bears  a 
nearly  constant  ratio  to  the  fat.  The  percentage 
of  water  also  varies  considerably.  The  causes  of 
the  variation  of  the  fat  have  already  been  noticed. 
The  proportion  of  albumin  is  very  largely  in- 
fluenced by  the  physical  condition  of  the  cow,  and 
it  has  been  shown,  notably  by  Van  Slyke  (see 
Chapter  X  ) ,  that  with  what  may  be  called  normal 
milk, — that  is,  milk  containing  from  3  to  4.5  per 
cent  of  fat, — the  proportion  of  casein  rises  or  falls 
in  almost  exact  ratio  with  the  fat,  but  when  the 
fat  rises  above  this  point  the  casein  does  not 
follow  in  the  same  proportion. 

A  notion  is  prevalent  that  the  percentage  of  fat 
in  the  milk  is  also  affected  by  the  age  of  the  cow ; 
that  during  the  first  and  second  periods  of  lactation 
the  young  cow  usually  gives  milk  poorer  in  fat 
than  when  she  is  mature.  During  tlie  years  of 
greatest  vigor  the  percentage  of  fat  is  supposed  to 
be  fairly  uniform  ;  but  in  cows  of  advanced  age  it 
may  sometimes  again  fall  to  a  low  point.  Recently 
some  records  have  been  published*  that  go  to  show 
that   the   age   of   the   cow   has   little,  if   any,  influence 

*Holstein  Friesian   Herd   Book,  vols.  13,  14,  15,  16,  17,     Cornell    University 
Agr.  Expt.  Station,  Biillet'n  No.  169, 


32 


Milk   and    Its    Products. 


ou  the  percentage  of  fat  in  the  milk.  In  the  one 
case  the  observations  were  made  upon  a  large  num- 
ber of  cows  of  all  ages,  for  a  week  at  a  time,  com- 
paratively early  in  the  period  of  lactation.  In  the 
other  the  observations  were  made  upon  a  single  herd 
extending  over  several  years,  and  the  percentages  of 
fat  are  the  average  for  the  whole  period  of  lactation, 
The  percentages  of  fat  for  the  different  ages  are  as 
follows  : 


'  Official "  u'eekly  tests  of 
Jdolstein-Friesian  cows. 


Observations  on   Cornell 
University  herd,  1891-8. 


2-year-oIds  .  .  . 

3-year-olds  .  .  . 

4-year-olds  .  .  . 

5-year-olds  .  .  . 

6-year-olds  .  .  . 

7-year-olds  .  .  . 

8-year-olds  .  .  . 

9-year-olds  .  .  • 

10-year-olds  .  .  .    . 
11-  and  12-year-olds 


No. 
of  Cows. 
•      147 

81 

59 

37 
.        36 


Average 
per  cent  fat. 
3.29 
3.31 
3.41 
3.42 
3.34 
3.25 
3.40 
3.37 
3.83 
3.57 


No. 
of  Cows. 
25 
25 
18 
12 


^0| 
57/ 


Average 
per  cent  fat. 
3.71 
3.71 
3.68 
3.60 
3.49 
3.68 

3.89 


The  breed  of  the  cow  also  influences  very  largely 
the  percentage  of  fat  in  the  milk.  Cows  of  certain 
breeds  normally  give  milk  much  richer  in  fat  than 
others. 

The  following,  compiled  from  a  large  number 
of  anal3ses  made  at  various  American  Agricultural 
Experiment  Stations,  will  give  a  general  idea  of 
the  average  composition  of  the  milk  of  the  more 
common  breeds,  so  far  as  it  relates  to  total  solids 
and  fat: 


Milk   of  Different   Breeds.  33 

Solids.  Fat. 

Jersey 14.70  5.35 

Guernsey 14.71  5.16 

Devon 14.50  4.60 

Short-horn 13.38  4.05 

Ayrshire.       12.61  3.66 

Holstein-Friesian 11.85  3.42 


The  variation  due  to  breed  includes  not  only  the 
amount  of  fat,  and  the  color  and  melting  point  of 
the  fat,  but  the  size  of  the  milk  globules.  In  some 
breeds  the  milk  globules  are  uniformly  large,  in 
others  extremely  small,  and  in  still  others  both  large 
and  small  globules  are  found. 

While  there  is  a  distinct  difference  in  the  qual- 
ity of  the  milk  of  the  different  breeds,  the  dif- 
ferent individuals  in  the  breed  also  vary  largely  in 
the  quality  of  the  milk.  The  difference  in  the 
percentage  of  fat  in  milk  from  different  cows  of 
the  same  breed  is  quite  as  great  as  the  average 
differences  between  the  breeds ;  that  is  to  say,  the 
difference  between  the  highest  and  lowest  percent- 
age of  fat  in  the  milk  of  different  individuals  of 
the  same  breed  is  as  great  as  the  difference  be- 
tween the  average  percentage  of  fat  in  the  breeds 
giving   the   richest    and    poorest    milk. 

The  variations  due  to  the  breed  of  the  animal 
extend,  of  course,  in  some  measure  to  the  butter 
made  from  the  milk.  This  is  particularly  true  of 
the  color  and  hardness  of  the  fat.  But  while 
these  differences  are  sufficient  in  amount  to  be 
characteristic,  they  scarcely  affect  the  quality  of 
the   butter   as   a   whole.      While   some   partisans   may 


34  Milk   and    Its    Products. 

contend  that  the  butter  made  by  their  favorite  breed 
is  of  superior  quality,  it  would  be  well-nigh  impos- 
sible, in  any  given  case,  by  an  examination  of  the 
butter,  to  say  from  what  breed  of  cows  it  had 
been  made.  Butter  of  the  very  best  quality  in  tex- 
ture, color  and  flavor  may  be  made  from  the  milk 
of  any    breed   of   cows. 


CHAPTER   III, 

THE    TESTING   OF  MILK. 

Milk  is  so  variable  in  composition,  and  so  ea- 
sily adulterated,  that  it  frequently  becomes  of  great 
importance  to  be  able  to  ascertain  with  a  fair  de- 
gree of  accuracy  the  composition  of  any  given 
sample  „ 

HISTORY    OF    MILK    TESTS. 

Qravimetric  analysis. — The  most  accurate  way  to 
determine  the  composition  of  milk  is  by  means  of  an 
exact  chemical  analysis.  The  constituents  of  milk 
which  it  is  most  frequently  necessary  to  determine 
are  the  total  solids  and  fat.  The  total  solids  are 
determined  hy  drying  an  accurately  weighed  portion 
of  the  milk  at  the  temperature  of  boiling  water 
until  it  no  longer  loses  weight.  The  residue  is  the 
total  solids,  and  its  weight,  divided  by  the  weight 
of  the  original  amount  taken,  will  give  the  percent- 
age of  total  solids.  The  fats  may  then  be  deter- 
mined by  extracting  the  residue  with  anhydrous 
ether  until  nothing  more  is  dissolved,  and  then 
evaporating  the  ether  and  weighing  the  resulting 
fat  directly.  Various  forms  of  apparatus  for  mak- 
ing these  determinations  have  been  devised  by  vari- 
es) 


36  Milk    and    Its    Products. 

ous  chemists,  a  considerable  number  of  which  give 
very  accurate  results.  Chief  among  these  methods 
for  determining  fat  and  total  solids  are  the  Babcock 
asbestos  method  and  the  Adams  paper -coil  method. 
In  order  that  these  determinations  may  be  made 
with  accuracy,  balances  of  extreme  delicacy,  and 
apparatus  more  or  less  complicated  and  requiring 
considerable  skill  in  its  manipulation,  are  necessary, 
so  that  for  ordinary  commercial  purposes  they  are 
practically  out  of  reach. 

History  of  milk  tests. — Although  consumers  of 
milk  had  felt  for  a  long  time  the  necessity  of 
some  means  of  protection  against  dishonest  dealers, 
it  was  not  until  the  development  of  the  factory  sys- 
tem of  manufacturing  cheese  (1850)  and  butter 
(1870)  that  some  means  of  easily  determining  the 
composition  of  milk,  particularly  as  to  fat  content, 
became  important  to  both  producers  and  manufac- 
turers. From  that  time  on  various  methods  have 
been  devised,  from  the  simple  expedient  of  raising 
the  cream  in  a  small  sample  of  milk  in  a  graduated 
glass  to  apparatuses  almost  as  complicated  and 
difficult  of  manipulation  as  the  gravimetric  methods 
themselves. 

Cream  gauges. — The  simplest  and  one  of  the 
earliest  methods  used  to  determine  the  quality  of 
milk  is  to  set  a  small  portion  of  it  under  such  con- 
ditions that  the  cream  would  be  thoroughly  thrown 
to  the  surface  and  easily  measured.  These  were 
known  as  cream  glasses,  cream  gauges,  or  cream- 
ometers,  and  to  a  certain  extent  served  a  useful  pur- 


Lactometers.  37 

pose  ;  but  it  was  soon  found  that  the  percentage  of 
cream  depends  not  so  much  upon  the  amount  of  fat 
present  in  the  milk  as  upon  the  size  of  the  globules 
and  the  conditions  under  which  they  are  brought 
to  the  surface,  and  that  the  percentage  of  cream 
does  not  necessarily  bear  a  constant  relation  to  the 
percentage  of   fat. 

Specific  gravity. — The  determination  of  the  spe- 
cific gravity  was  next  brought  into  use  as  a  means 
of  determining  the  quality  of  milk.  Inasmuch  as 
milk  is  slightly  heavier  than  water,  and  as  water  is 
the  most  common  adulterant  of  milk,  any  addition 
of  water  to  it  would  serve  to  lessen  its  specific 
gravity,  and  would  easily  be  detected  by  a  determi- 
nation of  the  specific  gravity.  To  determine  the 
specific  gravity  of  milk,  various  forms  of  specific 
gravity  hydrometers,  known  as  lactometers,  have 
been  devised.  They  were  formerly  very  much  more 
depended  upon  as  a  test  of  the  quality  of  milk  than 
at  present,  and  though  now  we  have  learned  that 
under  certain  conditions  a  simple  specific  gravity 
test  may  not  only  be  inaccurate,  but  entirely  mis- 
leading, still  they  are  of  cojisiderable  use  for  cer- 
tain purposes  and  in  connection  with  certain  other 
instruments. 

Lactometers . — In  devising  the  lactometer,  it  was  as- 
sumed that  1.029  was  as  low  as  the  specific  gravity  of 
any  unadulterated  milk  would  ever  fall ;  therefore  a 
hydrometer  was  devised,  the  scale  of  which  was  gradu- 
ated from  0  to  120,  the  0  marking  the  point  of  pure 
water,   or   a   specific   gravity   of    1.000,   and   100   cor- 


Milk   and   Its   Products. 


responding  to  the  assumed  least  specific  gravity  of 
milk,  or  1.029. 
If,  then,  in  any 
given  sample  of 
milk  the  lactom- 
eter fell  to  90, 
it  would  indicate 
the  presence  of  10 
per  cent  of  water  ; 
if  it  fell  to  75,  of 
25  per  cent  of 
water,  etc.  This 
form  of  lactometer 
is  now  known  as 
the  common,  or- 
dinary or  Board 
of  Health  lactom- 
eter. A  second 
form  of  lactometer 
in  common  use 
was  devised  by 
Quevenne,  and 
bears  his  name. 
The  scale  of  this 
hydrometer  is  or- 
dinarily graduated 
from  15  to  40,  the 
29  being  coinci- 
dent with  100  up- 
on the  ordinary  lac-  pjg  2.  comparison  of  graduation  on  lactometer 
fnmpf Pr     nnrl      wifh  ^^^"^^  '•  ^'  l^ydioineter  •  B,  ordinary  lactometer; 

lOmerer     ana      Wlin  O,  Quevenne  lactometer. 


1.000 

0 

1.005- 
1.010- 
1.016 
1.020- 
1.025- 

: 

10- 
20- 

30- 
40- 
60- 
60- 
70- 
80- 
90- 
100 

15- 
20- 
25- 

1.030- 
1.035- 

- 

A 

110- 
120- 

B 

30- 
35- 
40- 

c 

Relation  of  Quevenne  to  Ordinary  Lactometer.     39 

a  specific  gravity  of  1.029  upon  the  ordinary  hy- 
drometer. The  accompanying  sketch  (see  opposite 
page)  shows  the  relative  values  of  the  degrees  upon 
the  ordinary  hydrometer,  the  ordinary  lactometer  and 
the  Quevenne  lactometer.  With  the  Quevenne  lac- 
tometer the  specific  gravity  of  the  milk  can  be  at 
once  read,  a  degree  upon  this  scale  being  equivalent 
to  one  degree  of  specific  gravity.  Since  100  degrees 
upon  the  ordinary  lactometer  are  equal  to  29  degrees 
specific  gravity,  the  specific  gravity  may  be  obtained 
by  multiplying  the  ordinary  lactometer  reading  by 
.29  and  adding  1,000.  Twenty -nine  Quevenne  de- 
grees are  also  equivalent  to  100  ordinary  degrees, 
so  that  Quevenne  readings  may  be  changed  to  the 
ordinary  readings  by  dividing  by  .29,  and  ordinary 
readings  may  be  changed  to  Quevenne  readings  by 
multiplying   by  .29. 

The  relative  density  of  milk  varies  with  its  tem- 
perature, so  that  a  hydrometer  is  only  correct  at  one 
given  temperature.  Most  hydrometers  are  graduated 
for  a  temperature  of  60°  F.,  and  the  better  forms 
have  an  attached  thermometer ;  so  that  if  the  milk 
to  be  tested  varies  from  this  in  either  direction  a  cor- 
rection must  be  made.  As  the  density  increases  with 
a  reduction  of  temperature  and  decreases  with  a  rise 
of  temperature,  the  correction  must  be  subtracted  if 
the  temperature  is  too  low,  and  added  if  the  temper- 
ature is  too  high.  The  amount  of  such  correction 
for  the  Quevenne  lactometer  is  .1  of  a  lactometer 
degree  for  each  degree  of  temperature,  and  for  the 
ordinary   lactometer  one   lactometer  degree  for  each  3 


40  Milk   and    Its    Products. 

degrees  of  temperature.  In  no  event  should  the 
temperature  of  the  milk  to  be  tested  be  more  than  10 
degrees  warmer  or  colder  than  the  standard,  and  it  is 
much  better  if  the  temperature  does  not  vary  from 
the  standard  more  than  5  degrees  in  either  dii*ection. 
The  solids  in  milk  are  not  all  of  the  same 
specific  gravity  ;  some  are  heavier  and  some  lighter 
than  water.  The  fats  are  lighter,  the  other  solids 
are  all  heavier.  The  specific  gravitj^  of  the  milk, 
then,  depends  not  only  upon  the  amount  of  solids 
present  in  the  milk,  but  also  upon  theii'  relative 
proportions.  The  specific  gravity  of  milk  may  be 
affected  by  the  addition  of  any  substance  to  it  or 
the  abstraction  of  any  of  its  constituents.  Since 
some  of  the  constituents  of  milk  are  lighter  than 
water,  their  abstraction  in  whole  or  in  part  would  be 
followed  by  an  increase  in  density.  It  will  be 
readily  seen,  then,  that  if  a  part  of  the  fats  are  re- 
moved, the  specific  gravity  of  the  skimmed  or  partly 
skimmed  milk  will  be  heavier  than  normal,  and  the 
addition  of  a  certain  amount  of  water  or  other  sub- 
stance lighter  than  the  milk  would  only  serve  to 
bring  the  specific  gravity  back  to  the  normal  point. 
In  this  way,  if  it  is  done  skilfullj',  water  may  be 
added  to  milk,  and  cream  abstracted  from  it,  with- 
out affecting  the  specific  gravity  as  revealed  by  the 
lactometer,  and  a  very  inferior  sample  of  milk  might 
pass  as  perfectly  normal  if  the  lactometer  alone 
were  depended  upon  for  its  detection.  Mainly  for 
this  reason  the  lactometer  has  been  superseded  bj^ 
other  and  more  accurate  instruments. 


operation   of  Test    Chums.  41 

Churn  tests. — The  first  butter  factories  or  cream- 
eries were  managed  upon  what  is  known  as  the 
cream  -  gathering  system  :  that  is,  the  cream  was 
raised  and  skimmed  upon  the  farm,  and  it  alone 
taken  to  the  factor^'.  It  was  soon  found  that  the 
cream  varied  considerably  in  the  percentage  of  fat 
that  it  contained,  and,  moreover,  that  a  consider- 
able amount  of  milk  could  be  mixed  with  the 
cream  without  being  detected  by  ordinary  means. 
In  other  words,  the  managers  of  factories  learned 
that  cream  as  it  came  to  them  was  even  more 
variable  in  its  percentage  of  fat  than  whole  milk. 
In  all  of  the  earlier  factories  the  cream  was  paid 
for  simply  bj'  measure,  and  it  became  necessary  to 
devise  some  means  of  making  an  equitable  division 
among  the  different  patrons,  and  of  protecting  the 
factory  from  loss.  To  do  this,  what  was  known 
as  test  churns  were  devised.  At  the  time  of 
gathering  the  cream,  a  small  sample  (  a  pint  or 
quart)  of  each  patron's  cream  was  taken  in  a  sep- 
arate vessel.  These  were  taken  to  the  factory 
and  churned  separately'  in  small  tin  cans,  and  the 
butter  made  up  from  each.  The  butter -producing 
power  of  the  single  pint  or  quart  was  taken  as  a 
measure  of  the  butter  value  of  the  whole  amount 
of  that  patron's  cream,  and  the  proceeds  were  ap- 
portioned accordingly.  This  method  was  much  more 
just  than  a  simple  measure  of  the  cream,  but  it 
was  very  cumbersome.  It  required  delicate  manip- 
ulation in  order  to  make  all  of  the  little  pats  of 
butter    of   the    same    water    content,     and    the    small 


42  Milk  and   Its   Products, 

amounts  of  butter  so  made  were  of  inferior  com- 
mercial quality,  could  not  be  mixed  with  the  whole 
mass  of  butter,  and  entailed  a  considerable  loss 
upon  the  creamery. 

The  oil -test  churn  was  an  outgrowth  of  this 
method,  intended  to  remedy  its  defects,  and  was  in 
a  great  measure  successful.  In  operating  the  oil -test 
churn,  the  individual  samples  taken  from  each  patron 
were  very  much  smaller,  and  were  taken  in  small 
glass  tubes.  These  tubes  were  put  in  a  frame  and 
agitated  until  the  fat  was  di-awn  together  in  a  solid 
mass  ;  the  tubes  were  then  immersed  in  water  suf- 
ficiently warmed  to  melt  the  fat,  and  when  so 
melted  the  fat  would  float  upon  the  surface  of  the 
liquid  in  the  tube.  The  tubes  were  allowed  to 
become  cool,  were  then  a  second  time  agitated  to 
churn  any  particles  of  fat  that  had  escaped  the 
first  churning,  and  the  fat  remelted  ;  it  then  ap- 
peared in  the  form  of  a  clear  layer  of  liquid  upon 
the  top  of  the  contents  of  the  tube,  and  could  be 
readily  measured.  The  proportion  of  melted  fat 
so  obtained  was  taken  as  a  measure  of  the  butter 
value  of  the  cream  of  which  it  was  a  sample. 
This  test  was  generally  used  in  cream -gathering 
factories,  and  was  a  very  fair  measure  of  the 
butter  value  of  the  cream.  There  was  always  a 
portion  of  the  fat  remaining  unchurned,  but  in 
cream  it  was  a  small  percentage.  In  milk,  how- 
ever, it  was  a  much  larger  proportion,  and  the 
oil -test  churn  was  never  successfully  used  for  de- 
termining fat   in   milk. 


Lactohutyrometer  and   Bioscope .  43 

Inventions  for  testing  milk. — Several  instruments 
of  European  invention  have  been  described  for  the 
quick  determination  of  the  fat  in  milk.  Some  of 
them  make  volumetric  determinations  of  the  fat  or 
cream  ;  others  depend  simply  upon  the  opacity  of 
the  milk.  One  or  two  are  in  common  use  in 
Germany  and  Denmark,  but,  though  most  of  them 
have  been  introduced  in  the  United  States,  none 
have  come  into  general  use.  The  more  important 
of   these   are   the   following : 

MarcJiand^s  lactohutyrometer. — This  is  an  instru- 
ment for  quickly  determining,  volumetrically,  the 
fat  in  milk.  A  measured  sample  of  milk  is  intro- 
duced into  a  long  glass  tube  graduated  at  the 
upper  end.  A  certain  amount  of  acetic  acid  is 
added  and  thoroughly  mixed  with  the  milk,  after 
which  ether  is  added  to  dissolve  the  fat,  and  with 
the  aid  of  a  small  amount  of  heat  the  fat  is  col- 
lected into  the  upper  graduated  portion  of  the  tube 
and  read  off  volumetrically.  The  lactohutyrometer 
was  introduced  about  1877,  and  was  used  with 
more  or  less  success  for  a  time.  In  certain  sam- 
ples of  milk  it  was  found  to  be  difficult  to  get  a 
clear  separation  of  the  fat,  and  in  certain  other 
samples,  notablj^  the  milk  produced  from  various 
foods,  it  was  found  that  the  results  could  not  be 
relied  upon. 

Heeren^s  piosco2)e. — This  is  a  simple  little  instru- 
ment designed  to  test  the  quality  of  milk  by 
means  of  its  opacity.  It  consists  of  a  hard  rubber 
disc,    in   the   center   of  which   is   a   small   depression, 


44  Milk    and   Its    Products. 

and  the  surrounding  circle  painted  in  segments  of 
varying  shades  to  represent  cream,  very  rich  milk, 
normal  milk,  poor  milk,  etc.  A  drop  of  the  milk 
to  be  tested  is  placed  in  the  central  depression 
and  covered  with  a  glass  plate,  so  that  a  layer  'of 
uniform  thickness  is  always  obtained.  The  opacity 
of  this  drop  of  milk  upon  the  black  background 
of  rubber  is  then  compared  with  a  corresponding 
segment  of  the  circle.  In  so  far  as  the  fat 
measures  the  opacity  of  the  milk,  this  is  a  fairly 
reliable  test ;  and,  used  in  connection  with  a  specific 
gravity  lactometer,  a  person  with  some  experience 
can  readily  detect  suspected  samples  of  milk,  although, 
of  course,  it  is  not  possible  to  estimate  very  closely' 
the  amount  of  adulteration  or  the  quality  of  the 
milk.  The  pioscope  has  been  used  very  generally 
and  successfully  by  milk  inspectors  and  those  hav- 
ing  the  control   of   city   milk   supply. 

Feser^s  lactoscope  is  another  instrument  designed 
to  determine  the  quality  of  milk  by  opacity.  It 
consists  of  a  glass  cylinder,  in  the  center  of  which 
is  fixed  a  white  rod  graduated  with  black  lines. 
A  certain  amount  of  milk  is  put  into  the  cylinder, 
and  by  its  opacity'  renders  the  black  lines  upon 
the  central  standard  invisible.  Water  is  then  added 
to  the  milk  in  measured  quantity  until  the  black 
lines  can  be  seen,  the  amount  of  water  so  added 
indicating  the  quality  of  the  milk.  This  instru- 
ment is  more  delicate  than  the  pioscope,  but  it  can 
not  be  so  quickly  and  readily  used.  The  results 
it    gives    are    of  very    much     the    same    nature    and 


Various   European    Tests.  45 

value  as  those  obtained  by  the  use  of  the  pioscope, 
consequently  it  has  never  been  used  to  any  great 
extent. 

SoxhleVs  method. — In  testing  milk  by  this  method, 
the  fat  in  a  measured  quantity  of  milk  is  dissolved 
in  ether,  the  specific  gravity  of  the  ether  solution 
determined,  and  from  this  the  percentage  of  fat  is 
calculated.  The  greater  the  specific  gravity  of  the 
ether  solution  the  greater  the  percentage  of  fat, 
and  since  the  difference  in  the  specific  gravity  of 
fat  and  ether  is  considerable,  the  addition  of  a 
small  amount  of  fat  will  perceptibly  affect  the  specific 
gravity,  so  that  the  determination  is  a  very  delicate 
one.  The  determination  is  made  in  a  specially  de- 
vised apparatus  known  as  Soxhlet's  Aerometer.  It 
has  been  widely  adopted  in  Germany,  but  not  at  all 
in  the  United  States  outside  of  chemical  labora- 
tories. 

BeLaval  lactocrite. — This  is  a  machine  devised  by 
the  inventor  of  the  centrifugal  separator  to  esti- 
mate the  fat  in  milk  volumetrically.  The  sample 
to  be  tested  is  put  in  a  glass  tube  with  an  equal 
amount  of  concentrated  acetic  acid  containing  5  per 
cent  of  concentrated  sulphuric  acid,  and  the  mixture 
heated  for  a  few  minutes,  after  which  it  is  whirled 
in  a  centrifugal  machine  until  the  fat  is  brought  to 
the  center.  It  is  then  read  off  volumetrically.  The 
lactocrite  gives  a  very  close  determination  of  the 
fat  in  milk,  but  it  is  necessary  to  have  a  separator 
frame  in  which  to  whirl  the  apparatus,  which  makes 
it    somewhat    expensive. 


46  Milk   and   Its   Products. 

Fjord^s  control  apparatus. — This  apparatus,  in- 
vented by  the  late  Professor  Fjord,  of  Denmark, 
estimates  the  fat  by  measuring  the  solidified  cream. 
Glass  tubes  similar  to  those  used  in  the  oil -test 
churn  are  secured  in  a  frame  and  a  measured  quan- 
tity of  milk  put  in  each.  The  frame  holding  the 
bottles  is  then  whirled  in  a  centrifugal  separator 
frame  till  the  cream  is  completely  separated  and 
brought  together  in  a  compact  mass.  This  re- 
quires about  forty -five  minutes.  The  solid  mass 
of  cream  is  then  measured  with  a  scale  and  the 
fat  estimated  from  it  by  means  of  a  table  con- 
structed by  the  inventor.  This  apparatus  is  in 
very  common  use  in  Denmark,  but  has  never  been 
introduced    into  this   country. 

Development  of  milk  tests  in  the  United  States. — Up 
to  the  year  1888,  there  had  been  no  apparatus  devised 
which  would  determine  the  fat  in  milk  accurately, 
easily,  cheaply  and  quickly.  None  of  the  methods 
described  could  in  any  sense  supph'  the  place  of  the 
gravimetric  analysis,  even  for  commercial  purposes. 
The  oil -test  churn  came  the  nearest  to  it,  but  that 
was  of  no  use  for  milk,  and  at  this  time  the  separa- 
tor creamery  was  beginning  to  supplant  the  gathered- 
cream  factory,  and  the  demand  was  constantly 
stronger  for  a  means  of  determining  the  fat  in  milk. 
This  year  also  marked  the  establishment  of  the  na- 
tional grant  to  Agi'icultural  Experiment  Stations  in 
each  of  the  states,  and  one  of  the  first  problems  at- 
tacked by  the  chemists  of  these  stations  was  to  de- 
vise a  quick  method   for  the  determination  of   fat  in 


American    Tests.  47 

milk.  In  the  next  two  years  no  less  than  seven  dis- 
tinct methods  were  devised  by  chemists  of  Agricul- 
tural Experiment  Stations  for  this  purpose.  All  of 
them  were  much  better  than  any  that  had  hitherto 
been  known,  but  one  was  so  much  in  advance  of 
any  of  the  others  that  now  it  is  practically  the  only 
method  used  for  the  quick  determination  of  fat  in 
milk.  This  is  the  method  devised  by  Dr.  S.  M.  Bab- 
cock,  known  as  the  Babcock  test,  and  first  published 
in  July,  1890.  The  various  tests,  in  the  order  of 
their  publication,  were  as  follows  : 

SJiorVs  method. — This  method  was  invented  by 
F.  G.  Short,  at  that  time  chemist  of  the  Wisconsin 
Agricultural  Experiment  Station,  and  was  first  pub- 
lished in  Bulletin 'No.  16  of  the  Wisconsin  Agricul- 
tural Experiment  Station  for  July,  1888.  In  brief, 
the  method  consisted  in  converting  the  fat  in  the 
milk  into  a  soap  by  means  of  an  alkali,  and  then  dis- 
solving the  soap  by  an  acid,  setting  free  the  fat. 
The  process  was  rendered  complete  by  boiling  for 
several  hours.  The  determination  was  made  with  a 
measured  quantity  of  milk  in  a  glass  test  bottle  with 
a  narrow  graduated  neck,  into  which  the  fat  was 
raised  at  the  end  of  the  process  and  read  off  volu- 
metrically.  Considerably  difficulty  was  often  ex- 
perienced in  getting  a  clear  separation  of  the  fat 
from  the  contents  of  the  tube.  The  long  period  of 
boiling  was  also  an  important  drawback  to  the 
method. 

The  method  of  Failyer  and  Willard .—T\vi^  method 
was   devised  by    Professors   Failyer   and    Willard,   of 


48  Milk   and   Its   Products. 

the  Kansas  Agricultural  Experiment  Station,  and 
was  published  in  the  report  of  that  station  for  1888. 
In  it  the  solids  of  milk  were  destroyed  by  h\'dro- 
chloric  acid  and  the  fat  partially  separated  by  means 
of  heat.  The  fat  was  then  dissolved  in  gasoline,  and, 
after  evaporation  of  the  gasoline,  was  measured  in 
a  graduated  portion  of  the  tube  in  which  the  opera- 
tion was  performed.  It  gave  a  clearer  reading  of 
the  fat  than  Short's  method,  but  required  more  deli- 
cate manipulation,  particularly  in  heating  the  acid 
and  milk  together  and  in  evaporating  the  gasoline. 
The  time  required  was  considerably  less  than  with 
Short's  method. 

Parsons^  method. — This  method  was  devised  bv 
Professor  C.  L.  Parsons,  of  the  New  Hampshire  Ag- 
ricultural Experiment  Station,  and  published  in  the 
report  of  that  station  for  1888.  This  method  made 
use  of  caustic  soap  and  a  solution  of  soap  and  alcohol 
to  destroy  the  milk  solids,  after  which  the  fat  was 
dissolved  in  gasoline.  A  measured  quantity  of  the 
gasoline  solution  of  fat  was  then  taken,  the  gaso- 
line evaporated  from  it  and  the  fat  carefully  dried. 
The  free  fat  was  then  measured  in  a  scale,  and  by 
means  of  a  calculation,  the  percentage  of  fat  deter- 
mined. This  method  gave  very  good  results  in  the 
hands  of  several  different  operators.  It,  perhaps, 
required  a  little  more  delicate  manipulation  than 
some  of  the  others,  and  it  was  considerably  more 
complicated  than  Short's  method. 

The  Iowa  Station  test. — This  test  was  invented  by 
Professor  George  E.  Patrick,  the  chemist  of  the  Iowa 


Bahcoch   Test.  49 

Agricultural  Experiment  Station,  and  published  in 
Bulletin  No.  8,  February,  1890,  of  the  Iowa  Experi- 
ment Station.  In  this  test  the  solids  of  the  milk 
were  destroyed  by  a  mixture  of  acetic,  sulphuric  and 
hydrochloric  acids,  and  the  fat  brought  to  the  sur- 
face by  boiling.  The  test  was  made  in  a  flask  with 
a  narrow  graduated  neck.  A  measured  quantity  of 
milk  was  put  in  the  flask,  a  sufficient  amount  of 
the  acids  added,  and  the  whole  boiled  for  ten  or  fif- 
teen minutes.  The  Iowa  Station  test  was  a  great 
improvement  upon  any  that  preceded  it  in  point  of 
simplicity.,   accuracy  and  length  of  time  required. 

Cochran^ s  method. — This  method  was  invented  by 
C.  B.  Cochran,  of  the  Pennsylvania  State  Board  of 
Health,  and  published  in  the  Journal  of  Analytical 
Chemistry,  Vol.  III.,  page  381.  In  this  method 
the  solids  of  the  milk  other  than  the  fat  were  de- 
stroyed by  the  use  of  a  mixture  of  acetic  and  sul- 
phuric acids,  aided  by  boiling.  When  the  milk 
solids  were  thus  completely  disintegrated,  the  fat  was 
brought  to  the  surface  by  the  aid  of  ether,  and  then 
the  whole  mass  further  boiled  until  the  ether  was  all 
evaporated.  The  clear  melted  fat  was  then  meas- 
ured by  transferring  it  to  a  vessel  with  a  gradu- 
ated neck.  The  Cochran  method  was  simple  in 
details,  but  required  rather  delicate  manipulation  in 
transferring  the  melted  fat  from  one  vessel  to  an- 
other. It,  however,  gave  very  good  results  in  a 
comparatively  short  time. 

The  Bahcock  test.— This  test  was  invented  by 
Dr.  S.  M.  Babcock,  chemist   of    the    Wisconsin  Agri- 

D 


50  3Iilk   and   Its    Products. 

cultural  Experiment  Station,  and  published  in  Bul- 
letin No.  24,  July,  1890.  In  point  of  simplicity, 
accuracy,  ease  of  manipulation  and  time  required, 
this  test  is  so  much  better  than  any  that  have  pre- 
ceded or  followed  it  that  it  is  now  practically  the 
only  one  in  use.  To  destroy  the  solids  other  than 
the  fat,  Dr.  Babcock  makes  use  of  a  single  rea- 
gent, commercial  sulphuric  acid,  of  a  specific  gravity 
of  1.82,  and  to  separate  the  fat  from  the  remain- 
ing contents  of  the  test  bottle  centrifugal  force  is 
used,  hot  water  being  added  to  bring  the  contents 
of  the  flask  up  to  the  graduated  part.  The  test  is 
made  in  a  small  flask  with  a  narrow  graduated  neck. 

The  Beimling  test. — This  method  of  testing  milk 
was  devised  by  Messrs.  Leffman  and  Beam,  and  is 
sometimes  known  under  their  name,  though  the  ap- 
paratus was  patented  by  H.  F.  Beimling,  and  intro- 
duced under  his  name.  The  Beimling  test  was  in- 
troduced in  the  year  1890,  and  was  essentially  like 
the  Babcock  test,  the  exception  being  that  instead 
of  a  single  reagent  two  were  used,  one  ordinary 
commercial  sulphuric  acid,  as  in  the  Babcock  test, 
and  the  other  a  mixture  of  amyl  alcohol  and  com- 
mercial hydrochloric  acid.  Largely  because  of  the 
greater  inconvenience  of  using  two  reagents,  the 
Beimling   test   has   fallen   into   disuse. 

Tests  introduced  since  the  Bahcock  test. — Two  or 
three  tests  differing  but  slightly  from  the  Babcock 
have  been  introduced  since.  One  of  these  is  known 
as  Gerber's  method,  the  invention  of  a  German 
chemist.       The    form    of   the    testing    bottles    differs 


Babcock    Test. 


51 


somewhat  from  that  used  by  Dr.  Babcock  ;  less 
whirling  is  required,  and  the  same  reagents  are 
used   as    in   the   case    of  the  Beimling.      The  DeLaval 


Fig.  3.    Hand  centrifugal  for  Babcock  test. 

Separator  Company  has  also  introduced  an  appara- 
tus for  testing  milk  which  is  known  as  the  butyrom- 
eter.  In  this  test  a  single  reagent,  sulphuric  acid, 
is   used   to   set   free    the   fat.  The   form   of   the  ap- 


52  Milk   and   lis    Products. 

paratus  is  different  from  the  Babcock  test,  a  much 
higher  speed  of  whirling  is  used,  a  smaller  sample 
of  milk  is  taken,  and  the  fat  is  read  in  a  solid 
instead  of  a  liquid  form. 

DETAILS    OF    THE    BABCOCK    TEST. 

The  apparatus  used  in  testing  milk  by  the  Bab- 
cock method  consists  of  a  centrifugal  machine,  three 
pieces  of  glassAvare  and  commercial  sulphuric  acid. 

The  centrifugal  machine. — Many  forms  of  centri- 
fugal machines  are  in  use,  almost  every  manufacturer 
having  his  own  particular  style.  It  is  essential  that 
the  centrifugal  should  be  substantially  made  ;  that  it 
should  run  smoothly  and  steadily,  either  loaded  or 
empty,  and  that  it  should  be  capable  of  developing  a 
speed  of  900  revolutions  per  minute,  with  a  wheel 
20  inches  in  diameter.  The  centrifugals  so  made 
may  be  driven  either  by  hand  or  steam  power.  In 
the  hand- power  machines,  the  motion  is  transmitted 
both  by  belts  and  by  friction  cogs  ;  in  the  latter 
case  it  is  essential  that  care  be  taken  to  prevent 
loss  of  motion  through  the  friction  cogs  becoming 
worn. 

In  the  centrifugals  driven  by  steam  turbines,  or 
jets  of  steam  delivered  against  the  circumference  of 
the  revolving  wheel,  it  is  much  better  that  the 
steam  be  applied  at  some  little  distance  from  the 
revolving  bottles,  otherwise  too  great  a  degree  of 
heat  may  be  developed  in  the  machine.  Woll  has 
shown*    that,     in     those     steam     turbines     in     which 


♦Hoard's   Dairjinan,  March   9,  1900:    vol.  31,  p.  75. 


The   Bahcock    Test    Glassware. 


53 


steam  is  introduced  into  the  bottle  chamber  or 
where  the  cover  fits  so  tightly  that  no  cold  air 
enters  the  chamber  during  the  whirling ;  the  bottles 
are  often  heated  to  such  a  degree  that  the  reading 
is  made  too  large  because  of  the  expansion  of  the 
fat  at  the  high  temperature.  The  fat  should  be  read 
at  a  temperature  of  110°  F., 
but  up  to  140°  F.  the  expan- 
sion is  not  sufficient  to  cause 
material  error.  When,  how- 
ever, the  temperature  rises  to 
200°  F.  or  thereabout;  as  fre- 
quently occurs  under  the  con- 
ditions named  above,  the  error 
due  to  the  expan- 
sion of  the  fat  may 
amount  to  .15  to 
.3  per  cent.  In  all 
such  cases  the  bot- 
tles should  be  al- 
lowed to  cool  to  at 
least  140°  F.  before 
reading.  Those  cen- 
trifugals are  most 
satisfactory  in  which  provision  is  made  for  the  bottles 
to  assume  a  perfectly  horizontal  position  when  in  mo- 
tion and  a  perfectly  perpendicular  one  when  at  rest. 
The  gJassivare. —  The  glassware  consists  of  a  flask 
or  test  bottle  in  which  the  determination  is  made, 
a  graduated  pipette  for  measuring  the  milk,  and  a 
short     graduated    glass    cylinder    for    measuring    the 


Fig.   4.      Steam    turbine    centrifugal    for 
Babeock  test.     (See  opposite  page.) 


54  3IiU'    and   Its    Products.     ' 

acid.  The  most  essential  feature  of  the  glassware 
is  that  it  should  be  accurately  graduated.  This  in 
general  can  be  secured  by  always  procuring  the 
glassware    from    a    reliable    manufacturer   or    dealer, 


Fig.  5.    Forms  of  Babcock  test  bottles  ;    a,  ordinary  bottle  for  whole 
milk  ;    b,  bottle   for   skim  milk,  using  double   charge  of   milk 

c,  Ohlsson,  or  "  B.  &  W."  double-necked  bottle  for  skim  milk 

d,  e,  bottles  for  testing  cream  ;  /,  bottle  with  detachable  neck 
g,  h,  detachable  necks  for  butter  and  cream. 

though  suspected  glassware  may  be  tested  with  com- 
paratively little  difficulty.  The  neck  of  the  ordinary 
test  bottle  is  graduated  from  0  to  10,  each  divi- 
sion being  subdivided  into  five  parts.  The  gradua- 
tion  from  0   to   10   will   contain    a   volume  of  melted 


Testing    Butter,    Cheese   and    Cream,  55 

milk  fat  equivalent  to  10  per  cent  of  the  weight  of 
the  milk  taken.  Each  subdivision  of  the  scale, 
therefore,  represents  .2  of  1  per  cent.  The  capa- 
city of  the  graduated  portion  of  the  neck  is  two 
cubic  centimeters.  The  specific  gravity  of  melted 
milk  fat  at  a  temperature  of  120°  F.  is  assumed  to 
be  .9.  The  two  cubic  centimeters  will,  therefore, 
weigh  1.8  grams,  and  in  order  that  the  percentage 
of  fat  read  off  shall  be  percentage  by  weight  and 
not  by  volume,  18  grams  of  milk  must  be  taken. 
But  milk  has  an  average  specific  gravity  of  1.032, 
therefore  18  grams  of  milk  will  be  contained  in 
17.44  cubic  centimeters.  Two  cubic  centimeters  of 
melted  milk  fat  is,  therefore,  10  per  cent  by  weight 
of  17.44  cubic  centimeters  of  average  milk.  It 
has  been  found  by  trial  that  a  pipette  of  the  or- 
dinary form  graduated  at  17.6  cubic  centimeters 
will  deliver  slightly  less  than  17.5  cubic  centimeters 
of  milk.  The  graduation  of  the  ordinary  pipette 
should,  therefore,  be  17.6  cubic  centimeters.  A 
little  less  acid  than  milk  is  ordinarily  required,  and 
the  acid  measure  is  graduated  at  17.5  cubic  centi- 
meters, though  the  amount  of  acid  actually  used 
may  readily  vary  two  or  three  cubic  centimeters 
either    way    from    this    point. 

The  fat  in  the  various  products  of  milk  may 
be  as  readily  determined  by  means  of  this  test  as 
fat  in  the  milk  itself,  and  for  these  determinations 
various  forms  of  special  apparatus  have  been  de- 
vised. (Fig  5.)  For  testing  cream,  bottles  with  a 
capacity  greater  than    10    per   cent  are    in    use.       Of 


56  MilJc   (Old    Its    Prod  nets. 

these  there  are  two  forms.  In  one  there  is  a  bulb 
in  the  middle  of  the  neck,  and  graduations  above 
and  below.  Ordinarily  the  lower  graduations  have  a 
capacity  of  5  per  cent,  the  bulb  a  capacity  of  10 
per  cent,  and  the  upper  graduations  a  capacity  of 
10  per  cent.  The  use  of  this  form  of  bottle  re- 
quires that  when  the  fat  is  read  off  the  bulb  should 
always  be  completely  full,  and  the  upper  and  lower 
surfaces  of  the  fat  rest  on  the  upper  and  lower 
graduations  respectively.  Another  form  of  cream 
test  bottle  has  a  neck  much  wider  than  that  used 
for  ordinarj^  milk  testing.  Bottles  of  this  form  have 
a  capacity  up  to  35  per  cent,  or  even  more.  The 
graduations  are  usually  not  closer  than  .5  of  1  per 
cent.  This  form  does  away  with  the  awkwardness 
of  the  bulb  in  the  center,  but  it  is  not  possible 
to  read  the  column  of  fat  to  so  small  a  fraction, 
usually  to  not  less  than  .5  of  1  per  cent.  For 
testing  cream,  particularly  cream  that  is  rich  in  fat, 
a  special  pipette  is  necessary.  The  specific  gravity 
of  cream  containing  25  per  cent  of  fat  or  over  is 
nearly  that  of  water,  and  in  testing  cream  of  this 
quality  a  pipette  of  18  instead  of  17.6  cubic  cen- 
timeters capacity  is  used.  For  testing  skim -milk, 
where  it  is  desii'able  to  read  the  small  fractions  of 
1  per  cent,  two  forms  of  bottles  have  been  devised. 
In  one,  two  pipettes  full  of  milk  are  used,  and  the 
graduations  have  one -half  the  ordinary  value  ;  in  the 
other  form,  the  bottle  has  two  necks,  one  of  ordi- 
nary width  for  the  introduction  of  the  milk  and  acid, 
and    the    other   an    extremely    narrow    one,    in   which 


Calibrating    the    Glassivare.  57 

the  fat  is  measured.  With  this  last  it  is  possible 
to  read  easily  to  .05   of  1  per  cent. 

The  fat  in  the  solid  milk  products,  as  butter  and 
cheese,  may  also  be  conveniently  determined  by  the 
Babcock  test.  Since  butter  or  cheese  cannot  be 
measured,  it  is  necessary  that  the  sample  to  be 
tested  be  weighed.  Balances  sensitive  to  .1  of  a 
gram  are  sufficiently  delicate.  Either  18  grams  of 
the  substance  may  be  weighed,  in  which  case  the 
percentage  of  fat  is  read  directly  from  the  bottle ; 
or,  what  is  more  convenient,  any  amount  from  4  to 
8  grams  maj^  be  taken.  In  the  latter  case,  the 
observed  reading  of  fat  bears  the  same  proportion 
to  the  percentage  of  fat  in  the  substance  taken  that 
the  weight  of  the  sample  taken  bears  to  18  ;  and  the 
percentage  is  found  by  multiplying  the  observed  read- 
ing by  18  and  dividing  the  result  by  the  weight  of 
the   sample   taken. 

In  testing  butter  and  cheese,  it  is  convenient  to 
use  the  bottles  with  detachable  necks.  A  little 
water  should  be  added  to  the  bottle  before  the 
acid   is   put   in,    to   aid   in   the    solution    of   cheese. 

Calibration  of  glassware.— The  correctness  of  the 
graduation  of  the  glassware  may  be  tested  with  more 
or  less  accuracy  according  to  the  means  at  hand. 
The  bottles  are  all  graduated  on  the  assumption 
that  the  tubes  are  of  uniform  caliber.  The  0  and 
10  points  are  determined  experimentally,  and  the  in- 
tervening space  equally  divided  into  50  divisions 
with  a  dividing  engine.  The  spaces  should,  there- 
fore,  be  of  uniform   size,    and  if  the   eye  can  detect 


58  Milk    and   Its    Products. 

any  variation  in  the  size  of  the  spaces  such  bottles 
should  be  discarded.  Bottles  inaccurate  in  this 
respect  are  seldom  met  with  now.  When  the  test 
was  first  introduced  they  were  of  frequent  occur- 
rence. Bottles  maj'  be  readily  tested  with  a  pipette 
of  2  c.  c*  capacity.  Fill  the  bottle  carefully  with 
water  to  the  0  point,  wipe  out  the  neck  carefulh^ 
and  di'op  in  exactly  2  c.  c.  of  water.  It  should 
just  fill  the  neck  to  the  top  of  the  graduation. 
If  delicate  balances  are  at  hand,  the  bottle  may  be 
weighed  full  of  distilled  or  clean  rain  water  to  the 
0  point,  and  then  again  filled  to  the  10  point. 
The  difference  in  weight  should  be  exactly  2  grams. 
The  calibration  will  be  still  more  accurate  if  mer- 
cury instead  of  water  is  used  ;  2  c.  c.  of  mercury 
may  be  measured  out,  or,  what  is  still  better, 
weighed.  The  specific  gravity  of  mercury  is  13.59  ; 
two  c.  c.  will,  therefore,  weigh  27.18  grams.  This 
weighed  or  measured  quantity  of  mercury  is  intro- 
duced into  a  dry  bottle,  a  close-fitting  plug  is  then 
inserted  into  the  neck  of  the  bottle  exactly  to  the 
top  of  the  graduation,  the  bottle  is  then  inverted  ; 
the  mercury  should  exactly  fill  the  graduated  space. 
The  same  portion  of  mercury  can  then  be  used  to 
test  another  bottle,  and  with  care  to  have  the 
bottles  dry,  and  to  see  that  all  of  the  mercury  is 
transferred  each  time,  a  large  number  of  bottles  can 
be    easily   and   quickly   calibrated. 

The    pipettes      are    best     tested    by    weighing     a 
pipette   full   of   either   water   or   mercury ;   the  former 


*  Cubic  centimeter.    See  metric  system,  in  Appendix. 


Precmdions   in    Sampling   Milk.  59 

should  weigh  17.6  grams,  the  latter  239  grams. 
Any  bottle  or  pipette  that  varies  more  than  2  per 
cent   from   the    standard   should   be   discarded. 

Sampling  tJie  milk. — The  accuracy  of  the  test 
depends  wholly  upon  getting  an  accurate  sample  of 
the  milk  to  be  analyzed.  A  part  of  the  fat  so 
readily  separates  from  the  milk  in  the  form  of 
cream  that  milk  cannot  stand  even  for  a  short 
time  without  the  upper  layer  becoming  richer  and 
the  lower  layers  poorer  in  fat.  Even  in  milk 
freshly  di-awn  from  the  cow,  that  in  the  upper  part 
of  the  pail  will  be  considerably  richer  than  that 
below.  The  first  step,  then,  in  sampling  milk  is 
that  it  should  be  evenly  and  thoroughly  mixed. 
This  is  best  brought  about  by  pouring  from  one 
vessel  to  another  :  but  if  the  milk  has  stood  over 
night  and  a  layer  of  tough  cream  formed,  the  par- 
ticles of  cream  will  not  be  thoroughly  mixed  by  a 
single  pouring  from  one  vessel  to  another.  In 
all  such  cases,  the  sampling  must  not  be  done 
until  all  visible  portions  of  cream  have  disappeared 
in  the  mass  of  the  milk.  Various  forms  of  sam- 
pling tubes  or  "milk  thieves"  have  been  devised  for 
taking  samples  of  milk.  They  serve  the  purpose 
fairly  well,  but  are  not  to  be  depended  upon  in 
comparison   with    a  thorough    agitation  of  the  milk. 

Where  the  previous  night's  milk  is  carried  to  the 
factory,  the  agitation  enroute  and  the  stirring  inci- 
dent to  pouring  from  the  carrying  can  into  the 
weigh  can  are  ordinarily  sufficient  to  cause  a  pretty 
complete  mixture   of   the   milk  :    but   in   cold   weather 


60  3nn'    and   Its   Products. 

it  will  frequently  be  noticed  that  the  cream  is  not 
thoroughly  broken  up.  Under  such  conditions,  extra 
precautions  must  be  taken  to  secure  perfect  sam- 
pling. 

Composite  sampling. — In  testing  milk  at  factories, 
it  is  more  convenient  to  take  a  sample  every  day, 
and  make  one  test  of  the  mixed  samples  at  the  end 
of  a  week,  ten  days  or  two  weeks.  In  order  to  do 
this,  it  is  necessary  to  provide  a  suitable  receptacle 
for  the  milk  of  each  patron.  (  Pint  lightning -top 
fruit  jars  or  milk  bottles,  or  glass -stoppered  sample 
bottles,  are  most  convenient.  )  To  these  bottles  is 
added  each  daj^  a  small  portion  of  each  patron's 
milk,  together  with  some  preservative  for  preventing 
the  milk  from  souring.  The  preservatives  in  com- 
mon use  are  bichromate  of  potash,  corrosive  subli- 
mate, and  milk  preservaline.  Caustic  potash  and 
soda  may  also  be  used.  Neumann*  claims  to  have 
had  as  good  results  with  sodium  nitrate  as  with 
bichromate  of  potash.  Most  of  these  substances  are 
poisons,  and  render  the  milk  unfit  for  use  ;  the  jar 
should,  therefore,  be  plainly  labeled.  For  many 
reasons  the  bichromate  of  potash  is  to  be  preferred. 
It  gives  a  distinct  color  to  the  milk,  and  only  a 
small  ciuantity  of  it  is  necessary  to  prevent  the  milk 
from  souring.  Whatever  preservative  is  emploj'ed 
should  only  be  used  in  quantity  sufficient  to  keep 
the  milk  from  thickening.  Of  the  bichromate  of 
potash,  an  amount  sufficient  to  color  the  milk  a  bright 
lemon   yellow   is   all    that    is    necessar3\       In    taking 

♦Milch  Zeitung,   vol.   xxii.   p.   526. 


Measuring   the   Milk.  61 

composite  samples,  an  amount  proportionate  to  the 
amount  of  milk  delivered  should  be  taken  each  day. 
This  is  conveniently  done  by  the  use  of  the  Scovell 
Aliquot  Milk  Sampler,  which,  besides  serving  this 
purpose,  gives  the  advantages  of  a  milk  thief  in  that 
it  takes  milk  from  all  parts  of  the  vessel.  Where 
the  milk  varies  only  a  few  pounds  from  day  to 
day,  good  results  may  be  obtained  by  taking  a  uni- 
form amount  of  milk  for  the  sample  each  day,  but 
where  the  variation  in  quantity  is  considerable, 
aliquot    samplers    are   much    to   be    preferred. 

Making  the  test. — In  preparing  to  make  the  test, 
the  same  care  must  be  used  that  the  sample  shall 
be  thoroughly  mixed  and  perfectly  uniform,  that 
was  taken  in  mixing  the  milk  when  the  sample 
was  drawn.  In  measuring  the  milk,  the  pipette 
should  either  be  perfectly  dry,  or  rinsed  out  with 
the  milk  to  be  tested  immediately  before  measur- 
ing the  assay.  Where  a  large  number  of  samples 
are  to  be  tested,  the  latter  is  found  to  be  the  better 
practice.  The  greatest  care  should  be  taken  that  the 
milk  is  accurately  measured.  The  lower  end  of 
the  pipette  should  be  placed  about  midway  of  the 
sample  of  milk  and  the  pipette  filled  bj^  gentle 
suction  at  the  upper  end.  The  milk  should  be 
drawn  into  the  tube  above  the  mark  on  the  neck, 
and  the  end  of  the  forefinger  quickly  placed  over 
the  end  of  the  pipette,  the  pipette  being  steadied 
by  the  thumb  and  second  and  third  fingers  ;  hold- 
ing it  now  on  a  level  with  the  eye  between  the  eye 
and     the      light,     the     pressure      on    the     forefinger 


62  Milk   and    Its    Products. 

should  be  gradually  relaxed  and  the  milk  allowed 
to  flow  out  of  the  lower  end  drop  by  drop  until 
the  upper  edge  of  the  milk  rests  exactly  upon  the 
graduated  mark  on  the  side  of  the  pipette.  The 
milk  is  then  transferred  to  the  test  bottle,  and  this 
should  always  be  done  by  placing  the  end  of  the 
pipette  against  the  side  of  the  neck  of  the  bottle, 
relaxing  the  pressure  of  the  forefinger  gently  at 
first,  allowing  the  milk  to  flow  down  the  side  of 
the  neck.  If  this  is  not  done  there  is  danger  that 
the  neck  will  become  clogged,  and  a  part  of  the 
milk  be  blown  out  by  the  escaping  air.  When 
all  of  the  milk  has  flowed  from  the  pipette,  the  last 
few  drops  should  be  gently  blown  into  the  neck  of 
the  test  bottle.  The  utmost  care  must  be  taken 
that  all  of  the  milk  is  transferred  from  the  pipette 
to    the    test   bottle,    and  none   allowed   to  escape. 

TJie  acid. — The  next  step  is  the  addition  of  the 
acid.  The  acid  should  be  put  into  the  test  bottle  in 
such  a  way  that  it  will  rinse  down  any  milk  that 
has  adhered  to  the  sides  of  the  neck,  and  pass  be- 
tween the  milk  and  the  glass  in  reaching  the  bot- 
tom of  the  bottle.  As  soon  as  the  acid  is  added, 
the  milk  and  acid  should  be  shaken  together  with  a 
gentle  rotary  motion  until  all  of  the  curd  is  com- 
pletely dissolved,  care  being  taken  that  no  particles 
of  curd  are  thrown  into  the  neck  of  the  bottle. 
The  amount  of  acid  used  should  be  about  the  same 
in  volume  as  the  milk,  depending  somewhat  upon 
its  strength.  Ordinary  commercial  sulphuric  acid 
with    a   specific    gravity    of    1.82    will    require    about 


Finishing    the    Test.  63 

17.5  cubic  centimeters  to  completely  dissolve  17.6 
cubic  centimeters  of  milk.  If  the  acid  is  too  weak 
the  curd  will  not  be  completely  dissolved,  and  will 
appear  as  a  curdy,  fiocculent  precipitate  mixed  with 
the  lower  part  of  the  column  of  fat.  If  the  acid 
is  too  strong,  some  of  the  solids  of  the  milk  will 
be  charred,  and  will  appear  as  dark -colored,  fioc- 
culent particles,  either  mixed  with  the  fat  or  im- 
mediately under  them,  when  the  test  is  completed. 
Slight  differences  in  the  strength  of  the  acid  may  ])e 
overcome  by  adding  a  little  more  or  a  little  less,  ac- 
cording as  it  is  too  weak  or  too  strong,  but  satis- 
factory results  cannot  be  depended  upon  unless  the 
acid  is  of  the  right  strength;  viz.,  1.82  sp.  gr. 
Convenient  hydrometers  may  be  secured  for  a  tri- 
fling amount,  so  that  any  one  may  be  certain  of  the 
strength  of  his  acid.  The  sulphuric  acid  should 
be  kept  tightly  corked  in  a  glass  -  stoppered  bottle, 
because  when  exposed  to  the  air,  it  takes  up  water 
rapidly,  and  soon  becomes  too  weak.  While  it  is 
not  necessary  that  the  sulphuric  acid  should  be  chemi- 
cally pure,  some  of  the  cheaper  grades  of  commer- 
cial acid  often  contain  impurities  that  seriouslj' 
affect  the  results,  causing  black  specks  to  appear  in 
the  neck  of  the  bottle.  A  reasonably  pure  commer- 
cial acid  should  always  be  used,  and  can  be  secured 
at  a  trifling  cost  above  the  impurer  forms. 

^¥llirling. — When  the  acid  has  been  added  and 
thoroughly  mixed  with  all  of  the  samples,  they  are 
put  into  the  centrifugal  machine  and  whirled  steadily 
for  five  minutes.       At  the  end    of    this  time  the  ma- 


64 


3IiU'    and   Its    Products. 


-B 


chine  is  stopped,  and  the  bottles  are  filled  with 
warm  water  to  the  bottom  of  the  neck.  They  are 
then  whirled  a  second  time  for  two  minntes,  when 
water  is  again  added  up  to  about  the  8  per  cent 
mark  on  the  neck  of  the  bottle,  after 
which  the}'  are  given  a  whirl  for  one  min- 
ute. The  bottles  are  then  taken  out  and 
cread  as  rapidly  as  possible. 

Reading. — The  reading  should  be  taken 
at  a  temperature  between  110°  and  140° 
F.,  at  which  temperatures  the  fat  will  be 
completely  fluid.  The  test  should  be  made 
in  a  room  at  a  temperature  not  less  than 
70  F.,  or  if  the  room  is  much  colder 
some  means  should  be  taken  to  prevent 
the  bottles  from  becoming  cool  until  all  are 
read.  Much  skill  and  facility  can  be 
attained  by  practice  in  reading  the  bottles 
rapidly  and  accurately.  In  reading  the 
bottles,  the  reading  should  be  made  as 
shown    in    the    diagram,   the    lower   reading 


Fig.   6.    Dia-  froui    tlic    extreme     lower    curved    surface 

gram  of  neck    /  -r-i-  />\  i       xi  t  ^ 

of   Babeock  [a,  Fig.    6),  and    the    upper    reading    from 
the  reading  thc     extreme     top    of     the    column    of    fat, 
made    be-  {!) ,   uot    c.  Fig.    6),  tlic    difference  between 
points    a-b,  tlic    lowcr    and    upper    reading    giving    the 
percentage    of    fat.       The    reason   for   read- 
ing in    this   way    is  that  a  small    amount  of   residual 
fat    is  left  mixed  with    the  other  fluids  in  the  bottle. 
This  is  composed   of   the  smaller  globules  of    fat,  and 
the    amount     is     practically    uniform,    and    has    been 


Estimation    of  Solids   not   Fat.  65 

found  to  represent  about  the  amount  occupied  by 
the  curved  surfaces  in  the  neck  of  the  bottle, 
due  to  the  capillary  attraction  between  the  fat  and 
the   glass. 

Cleaning  the  glassware. — Good  results  cannot  be 
secured  unless  the  glassware  is  kept  clean  and 
bright.  This  can  easily  be  done  with  yevy  little 
trouble.  As  soon  as  the  bottles  are  read,  and  while 
they  are  still  hot,  the  contents  should  be  emptied 
out.  The  hot  acid  and  water  will  carry  out  with 
it  the  larger  part  of  the  fat  in  the  neck  of  the 
bottle.  The  emptied  bottle  should  then  be  rinsed 
once  in  warm  water  and  once  in  hot  water  containing 
some  alkali,  either  washing  soda  or  any  of  the  va- 
rious washing  powders,  and  then  rinsed  with  either 
warm  or  cold  water  until  they  are  perfectly  clean. 
With  these  precautions  no  difficulty  w^ill  be  expe- 
rienced in  keeping  the  bottles  clean  and  bright. 

By  the  use  of  the  lactometer  in  connection  with 
the  percentage  of  fat,  a  close  approximation  to  the 
percentage  of  total  solids,  or  solids  not  fat,  may  be 
made.  Numerous  formulge  for  this  purpose  have 
been  devised.  Their  application  is  explained  and  il- 
lustrated   in   Part  A  of  the  Appendix. 


CHAPTER   IV. 

THE  FERMENTS   AND   FERMENTATIONS   OF  MILK, 
AND  THEIR    CONTROL. 

Milk,  when  it  is  first  drawn,  is  a  limpid  fluid 
with  a  slight  odor,  mildly  sweetish  taste,  and  faint 
alkaline  reaction.  In  fact,  milk  often  shows  the 
amphoteric  reaction  ;  that  is,  it  will  give  the  acid 
reaction  with  blue  litmus  paper  and  the  alkaline 
reaction  with  red.  Almost  immediately  after  it  is 
drawn,  milk  begins  to  undergo  a  change,  and  within 
a  short  time  will  show  a  distinct  acid  reaction. 
The  degree  of  aciditj^  increases  with  the  age  of  the 
milk.  Soon  changes  begin  in  the  other  milk  con- 
stituents, and  in  a  comparatively  short  time,  the  de- 
composition is  so  great  that  the  milk  can  no  longer 
be  used  for  food.  The  sugar  is  the  first  constit- 
uent of  the  milk  to  undergo  change,  afterwards 
the  albuminoids  are  attacked,  and  lastly  the  fats. 
These  changes  are  not  due  to  any  instability  of  the 
organic  compounds  in  the  milk,  but  to  the  effect 
of  various  vegetable  germs  that  gain  access  to  the 
milk  after  it  is  secreted,  and,  living  and  growing 
in  the  milk,  bring  about  the  changes  mentioned. 
These  changes  are  called  fermentations,  and  the 
agents  that  bring  them  about  ferments.  Milk  con- 
taining   no     germs     of    fermentation,     or    milk    from 


General    Characters   of  Bacteria.  67 

which  they  have  all  been  removed,  is  said  to  be 
sterile.  The  germs  found  in  milk  belong  to  the 
lowest  orders  of  the  vegetable  kingdom.  Most  of 
them  are  included  in  the  bacteria,  although  many 
yeasts  and   moulds  are  frequently  found   in   milk. 

The  bacteria. — The  bacteria  are  extremely  minute 
bodies  consisting  of  a  single  cell  filled  with  protoplasm. 
They  are  of  three  general  forms,— spherical  (coccus); 
rod -like  or  cylindrical  (bacillus),  and  curved  or  wavy 
(spirillum).  They  reproduce  by  fission ;  that  is,  the 
cell  elongates  slightly  in  the  direction  of  its  longer 
axis,  and  a  partition  is  formed  across  the  cell  trans- 
versely, and  two  individuals  exist  where  there  was 
but  one  before.  These  may  break  away  and  form 
separate  bacteria,  but  often  they  are  kept  .  together 
in  various  ways.  Many  forms  are  endowed  with 
motion,  and  all  require  a  liquid  or  semi -liquid  me- 
dium for  growth  and  development,  though  many 
may  exist  for  long  periods  of  time  in  a  dry  condi- 
tion. Like  other  plants,  in  order  to  grow  and  de- 
velop, the  bacteria  must  have  suitable  food.  They 
require  for  their  sustenance  carbon,  hydrogen,  oxy- 
gen and  nitrogen,  together  with  small  amounts 
of  mineral  matters.  Organic  compounds  are  more 
available  for  food  supply  than  simple  inorganic 
salts.  Substances  like  sugar  and  the  various  al- 
buminous compounds  are  admirably  suited  for  their 
food.  In  ordinary  milk  nearly  all  kinds  of  bacteria 
find  an  adequate  and  easily  available  food  supply 
in  a  medium  favorable  to  their  growth,  so  that  not 
only  the   forms   of   bacteria   ordinarily  found  in  milk, 


68  Milk   and   Its   Products. 

but  almost  any  others,  will  readily  live  and  grow 
should  they  gain  access  to  milk.  Nearly  all  forms 
of  bacteria  are  sensitive  to  conditions  of  tempera- 
ture. The  range  of  temperature  in  which  they 
thrive  the  best  and  grow  most  rapidly  is  rather 
narrow,  though  there  is  a  considerable  range  above 
or  below,  in  which  they  will  still  grow  and  develop. 
The  temperature  at  which  any  given  germ  will  grow 
most  rapidly  is  called  the  optimum  temperature,  and 
the  optimum  temperature  varies  widely  with  the 
various  classes  of  organisms,  though  by  far  the 
larger  number  of  bacteria  find  their  optimum  point 
between  75°  to  100°  F.,  and  a  higher  temperature 
not  only  stops  their  growth,  but  if  sufficiently  high 
kills  them  outright.  A  temperature  of  135°  F.  kills  a 
large  number  of  germs.  Very  few  are  able  to  live 
above  a  temperature  of  180°,  and  none  can  with- 
stand the  temperature  of  boiling  water,  212°,  for 
more  than  a  few  minutes.  If  heat  is  accompanied 
by  moisture  it  is  much  more  effective,  so  that  heat 
applied  in  the  form  of  live  steam  is  the  best  means 
of  destroying  the  life  of  these  germs.  Under  the 
influence  of  cold  the  germs  become  inactive,  and 
some  kinds  are  killed  by  a  sufficient  degree  of  cold, 
but  very  many  kinds  are  able  to  withstand  any 
degree  of  cold  possible  to  be  produced  for  long  pe- 
riods of  time. 

Under  certain  conditions  bacteria  are  able  to  as- 
sume an  inactive  condition,  or  spore  form.  In  do- 
ing this,  the  protoplasm  shrinks  into  a  hard,  glisten- 
ing mass,  and   contracts   toward  one  end    of  the   cell. 


Distribution   of  Bacteria,  69 

or  the  wall  cell  thickens  and  encloses  the  proto- 
plasm. In  the  spore  condition  the  bacteria  are  in- 
active, but  are  able  to  endure  much  greater  extremes 
of  heat,  cold  or  moisture  than  when  active.  When 
the  conditions  of  growth  become  again  favorable,  the 
spore  again  becomes  active,  or  is  said  to  germinate, 
and  the  vital  processes  are  resumed. 

Bacteria  are  widely  distributed  through  nature. 
In  fact,  there  are  very  few  places  where  they  may 
not  be  found.  They  are  so  light  and  small  that 
they  float  readily  in  the  atmosphere,  particularly  when 
accompanied  by  particles  of  dust.  They  are  found 
in  all  rivers  and  streams,  upon  the  surface  of  the 
earth,  and  upon  all  organic  matter.  In  fact,  they 
are  universally  distributed.  By  far  the  larger  num- 
ber are  not  only  perfectly  harmless  but  positively 
beneficial.  They  serve  to  transform  dead  organic 
matter  into  its  original  condition,  and  so  act  as 
scavengers.  Others,  like  the  milk  ferments,  bring 
about  specific  changes  in  some  definite  substances, 
while  still  others,  a  large  class,  are  the  specific 
causes  of  various  diseases  in  men  and  animals. 

Presence  of  bacteria  in  milk. — In  ordinary  milk, 
bacteria  are  always  present  in  large  numbers.  These 
gain  access  to  the  milk  from  the  atmosphere,  from 
the  bodies  of  the  animal  and  the  milker,  through 
contact  with  the  vessels  into  which  the  milk  is 
drawn,  and  to  some  extent  through  the  udder  of  the 
animal.  The  milk  when  secreted  is  sterile.  So 
far  as  is  known,  no  bacteria  can  pass  through  the 
digestive   organs    and    blood    vessels    of    the     animal 


70  Milk   and    Its   Products. 

and  appear  in  the  milk.  If  the  udder  is  the  seat 
of  disease  due  to  the  growth  of  bacteria,  such  bac- 
teria may  find  their  way  into  the  milk  ducts  and 
infect  the  milk.  In  one  other  waj'  the  animal  may 
be  said  to  be  a  source  of  infection  with  bacteria. 
•The  end  of  the  teat  of  the  animal  is  always  more 
or  less  moist.  Bacteria  coming  in  contact  with 
such  surface,  moistened  with  milk,  find  there  not 
only  food  in  proper  form  for  their  growth,  but  a 
temperature  sufficient  to  make  them  active.  They 
begin  to  multiply,  and,  working  their  way  through 
the  orifice  of  the  teat,  find  milk  in  larger  supply,  and 
a  temperature  still  more  favorable  for  their  growth. 
They  increase  and  multiply,  under  such  conditions, 
with  remarkable  rapidit}',  and  so  work  their  way 
upward  through  the  milk  cistern  and  into  the  larger 
milk  ducts,  so  that  the  milk  first  drawn  from  the 
animal  alwaj'S  contains  a  greater  or  less  number  of 
bacteria.  For  this  reason  it  is  not  an  easy  matter 
to  secure  perfectly  sterile  milk  direct  from  the  cow, 
though  w^ith  great  care  in  disinfecting  the  udder 
and  removing  the  larger  part  of  the  milk  from  it, 
perfectly   sterile   milk   has   been   obtained. 

Kinds  of  bacteria  in  milk. — Almost  any  of  the 
known  forms  of  bacteria  may  live  and  grow  and  oc- 
casionally be  found  in  milk.  Normally,  however,  com- 
paratively few  forms  of  bacteria  are  present.  The 
greater  part  of  these  are  forms  which  cause  various 
changes  in  the  constituents  of  milk,  and  are  known 
as  ferments,  and  the  changes  which  they  induce  as 
fermentations.     Beside  these   fermentations,  there  may 


Kinds   of  Milh   Fermentations.  71 

be  found  in  the  milk  the  bacteria  of  any  germ  dis- 
ease with  which  the  animal  may  be  afflicted,  or  which 
may  be  carried  into  the  milk  through  the  atmosphere, 
the  water  used  in  cleansing  utensils,  or  the  persons 
of   individuals  suffering   from    the    disease. 

The  fermentations  of  milk. — The  normal  fermenta- 
tions to  which  milk  is  subject  may  be  conveniently 
divided  into  three  classes.  First,  those  which  feed 
upon  and  cause  changes  in  the  milk-sugar,  known  as 
lactic  fermentations.  Second,  those  that  feed  upon 
and  cause  changes  in  the  albuminoids  of  the  milk  ; 
these  in  turn  are  of  two  classes,  peptogenic  and  pu- 
trefactive. Third,  those  which  attack  the  fats,  and 
are  known  as  butyric  fermentations.  Besides  these, 
which  may  be  called  normal  fermentations,  in  that 
they  will  easily  occur  in  any  sample  of  milk  if  left  to 
itself,  there  are  a  large  number  of  other  fermentations 
which  may  be  called  abnormal,  from  the  fact  that 
they  occur  only  in  isolated  localities,  or  from  time 
to  time.  These  abnormal  fermentations  include  one 
which  causes  the  casein  of  milk  to  coagulate  without 
the  development  of  lactic  acid,  known  as  sweet  curd- 
ling ;  another  which  causes  a  peculiarly  ropy  or  slimy 
condition  of  certain  constituents  of  milk  ;  still  an- 
other that  results  in  the  formation  of  an  intensely 
bitter  product  in  the  milk ;  an  alcoholic  fermenta- 
tion, and  several  fermentations  which  result  in  the 
production  of  various  colors,  collectively  known  as 
chromogenic  fermentations.  An  illustration  of  this 
class  is  seen  in  the  well-known  "bloody  bread," 
which  is  caused  by  the  growth  of  Bacillus  prodigiosus. 


72  Milk    and   Its   Products. 

This  germ  is  occasionally  found  in  milk,  and  imparts 
to  it  a  red  color  which  is  easily  confounded  with 
the  red  color  due  to  the  presence  of  blood  from  a 
wounded  udder.  A  single  germ  rarely  occasions 
more  than  a  single  fermentation .  Often  two  or  more 
are  combined  in  the  fermentation,  and  in  many  cases 
there  are  a  large  number  of  different  germs  that 
bring  about  the  same  fermentation.  This  is  notably 
true  of  the  lactic  and  putrefactive  fermentations. 
The  effect  of  the  various  fermentations  is  such  as  to 
destroy  the  value  of  the  milk  as  such,  if  they  are  al- 
lowed to  proceed  to  any  great  length  ;  but  the  manu- 
facture of  butter  is  greatly  aided  by  many  of  these 
fermentations,  and  the  presence  of  certain  germs  is 
absolutely  indispensable  to  the  manufacture  of  cheese. 
Relation  of  milk  bacteria  to  the  human  system. — By 
far  the  greater  number  of  germs  ordinarily  found  in 
milk  are  absolutely  harmless,  and  may  be  taken  into 
the  human  system  in  large  numbers  with  perfect 
impunity,  the  germs  of  specific  disease  excepted,  and 
with  these  latter  it  is  the  products  formed  from  their 
growth  rather  than  the  germs  themselves  from  which 
danger  comes.  There  are  probably  no  germs  normally 
found  in  milk  that  may  be  classed  as  harmful.  This 
is  also  true  of  a  considerable  number  of  fermen- 
tation products  resulting  from  the  growth  of  the 
germs  in  the  milk.  Many  of  these  products  give 
to  the  milk  or  its  product  an  unpleasant  taste  or 
physical  appearance,  but  are  otherwise  perfectly 
harmless.  There  are,  however,  certain  germs  which 
produce   a   fermentation   which   results  in    the  forma- 


The   Lactic   Acid    Germ.  73 

tion  of  poisonous  products.  These  products  are  the 
causes  of  the  serious  or  even  fatal  results  that  fol- 
low the  consumption  of  milk,  cheese,  ice-cream,  or 
other  products  containing  them.  They  are  collect- 
ively known  as  ptomaines.  To  one  in  particular, 
that  has  frequently  been  found  in  cheese,  the  name 
tyrotoxicon  (cheese -poison)  has  been  given.  They 
have  been  studied  by  Vaughn*  and  others,  but 
their  origin  is  still  obscure.  The  germs  producing 
these  poisonous  products  are  of  comparatively  in- 
frequent occurrence. 

In  general,  the  various  classes  of  fermentations  do 
not  readily  take  place  at  the  same  time.  The  active 
growth  and  development  of  one  germ  acts  more  or 
less  as  a  retarding  force  upon  the  growth  and  de- 
velopment of  other  germs. 

Lactic  fermentations. — Under  this  group  we  include 
all  of  those  germs  which,  living  and  growing  in 
milk,  feed  upon  the  sugar,  causing  it  to  change  to 
lactic  acid.  It  was  formerly  supposed  that  the  forma- 
tion of  lactic  acid  in  the  milk  was  entirely  due  to  the 
action  of  a  single  germ,  described  by  Hueppe,  and 
called  Bacillus  acidi-lactici,  or  the  lactic  acid  germ. 
It  is  now  known  that  there  are  at  least  twenty  different 
germs  that  may  produce  lactic  acid,  and  in  all  prob- 
ability there  are  many  more.  The  lactic  acid  germs 
are  the  most  common  and  most  numerous  germs 
found  in  milk,  and  ordinarily  the  lactic  fermentations 
are  the  first   to  take  place.      They  begin   their   opera- 


*  Vaughn-Novy.    Ptomaines  and  Leucomaines,  Philadelphia,  1896. 


74  Milk   and   Its    Prochicts. 

tions  almost  immediately  after  the  milk  is  drawn,  and 
continue  until  the  maximum  amount  of  lactic  acid  has 
been  produced.  In  the  lactic  acid  fermentations  one 
molecule  of  milk-sugar  (C12H22O11  —  H2O)  breaks  up 
into  four  molecules  of  lactic  acid  (CsHgOs)  without 
the  formation  of  any  secondary  or  by-product.  The 
presence  of  the  lactic  acid  serves  to  coagulate  the 
casein,  so  that  curdling  of  the  milk  is  always  an 
accompaniment  of  the  lactic  fermentation  after  it 
has  reached  a  certain  stage.  The  presence  of  lactic 
acid  is  unfavorable  to  the  growth  of  the  ordinary 
germs  of  lactic  fermentation,  and  when  a  certain 
amount  of  lactic  acid  has  been  formed  (about  .8  of  1 
per  cent  of  the  whole  milk ) ,  the  further  develop- 
ment of  lactic  acid  ceases.  In  milk  of  ordinary 
quality,  this  occurs  when  about  one -fourth  of  the 
milk-sugar  has  been  changed  to  lactic  acid.  If  the 
acid  be  neutralized  with  an  alkali,  the  fermentation 
will  then  proceed  until  another  portion  of  milk-sugar 
has  been  changed  to  lactic  acid,  showing  that  the 
lactic  acid  simpl}'  prevents  the  growth  of  the  germs, 
and  does  not  kill  them.  Lactic  acid  germs  are  most 
active  at  temperatures  between  80°  and  100°  F.;  at 
temperatures  below  80°  they  gradually  lose  their  ac- 
tivity, and  below  50°  little  or  no  lactic  acid  will  be 
formed.  At  these  low  temperatures  they  are  simply 
inactive,  not  dead.  At  a  temperature  of  105°  F., 
the  lactic  germs  become  inactive,  and  a  large  propor- 
tion of  them  are  killed  at  a  temperature  from  135° 
to  140°  F.  In  milk,  lactic  acid  fermentation  means 
simply  soui'ing,  and  it  renders  the  milk  unfit  for  use, 


Putrefactive   Fermentations.  75 

almost  wholly  because  the  taste  is  unpleasant  .to 
the  ordinary  palate.  A  large  amount  of  lactic  acid 
is,  perhaps,  injurious  to  young  and  delicate  or  weak 
digestive  organs,  but  ordinarily  is  harmless.  Lactic 
acid  fermentations  are  extremely  important  in  the 
processes  of  both  butter  and  cheese  manufacture, 
and  their  relations  to  these  processes  will  be  dis- 
cussed  in    detail    in   the   proper   place. 

Fermentations  affecting  the  albumitioids. — These  in- 
clude ordinary  putrefactive  fermentations,  peptogenic 
fermentations,  and  fermentations  resulting  in  the  for- 
mation of  poisonous  products.  These  fermentations, 
as  a  rule,  do  not  thrive  in  the  presence  of  a  strong 
lactic  fermentation,  so  that  ordinarily  they  do  not 
manifest  themselves  in  milk  unless  the  conditions  are 
peculiarly  favorable  for  their  development  and  un- 
favorable for  the  development  of  lactic  acid.  Many 
of  the  putrefactive  fermentations  will  go  on  at  a 
lower  temperature  than  the  lactic  fermentations  do  ; 
hence  it  is  often  found,  when  milk  is  kept  at  a  low 
temperature  in  order  to  keep  it  from  souring,  that 
after  a  certain  time  it  becomes  bitter  or  foul -smell- 
ing. This  condition  is  caused  by  some  one  of  the 
characteristic  putrefactive  fermentations.  The  putre- 
factive germs  also  readily  take  on  the  spore  form, 
and  in  this  condition  are  not  so  readily  killed  by 
heat.  The  putrefactive  fermentations  usually  result 
in  the  formation  of  bitter  or  other  unpleasant  flavors 
and  disagreeable  odors,  and  they  are  frequently  ac- 
companied by  a  considerable  evolution  of  gas.  Pep- 
togenic  fermentations   are   those    which    exert    a   pep- 


76  Milk  and  Its  Products. 

tonizing  or  digestive  action  upon  the  albuminoids. 
By  their  action  the  casein  is  first  coagulated,  and 
finally  liquefied  or  changed  into  a  peptone. 

Butyric  fermentations.  —  The  butj'ric  ferments  at- 
tack the  fats,  and  result  in  the  formation  of  bu- 
tyric acid.  They  produce  the  peculiar  condition 
found  in  cream  and  butter  known  as  rancidity,  and 
do  not  usually  manifest  themselves  very  strongly  in 
the  milk. 


Control    of    Fermentations. 

Since  fermentations  always  occur  in  milk  that  is 
kept  for  any  considerable  time,  and  since  they  exert 
so  powerful  an  influence,  not  only  upon  the  milk 
but  upon  the  products  manufactured  from  it,  the 
question  of  their  control  is  one  of  prime  importance. 
The  three  chief  means  of  such  control  are  :  First, 
prevention  of  infection  ;  second,  prevention  of  the 
growth  of  germs  already  present  ;  third,  destruction 
of   germs    already  present. 

Prevention  of  infection. — The  greatest  source  of 
infection  comes  from  the  body  of  the  animal  and 
from  the  air  of  the  stable.  The  germs  are  always 
present,  adhering  to  the  hair  of  the  animal,  and  par- 
ticularly to  any  particles  of  dust  or  dirt.  In  order, 
then,  that  the  animal  shall  not  be  a  source  of  infec- 
tion, it  is  necessary  that  she  be  carefully  curried 
and  the  udder,  teats,  flank,  thighs  and  lower  parts 
of  the  belly  wiped  off  with  a  damp  cloth  immediately 


Prevention   of  Infection.  11 

before  milking.  It  is  of  course  necessary,  also,  that 
the  hands  and  clothes  of  the  milker  should  be  as 
carefully  attended  to  in  this  respect  as  is  the  body  of 
the  cow.  The  bacteria  find  in  the  excrements  abun- 
dant food  for  growth  and  development,  and  are  al- 
ways found  in  large  numbers  where  such  excrements 
are  allowed  to  collect  ;  and  when  dirt  of  this  sort  ac- 
cumulates and  becomes  dried,  the  dust  floating  in  the 
air  always  carries  with  it  large  numbers  of  germs. 
The  germs  are  also  found  in  large  numbers  accom- 
panying the  dust  arising  from  hay  and  other  dried 
forage.  This  being  the  case,  it  is  essential  not  only 
that  the  stable  should  be  kept  scrupulously  clean, 
but  that  the  air  should  be  free  from  dust,  partic- 
ularly at  times  when  milking  is  going  on.  Thor- 
oughly sweeping  and  then  sprinkling  the  stable 
floors  an  hour  or  two  before  the  milking  will  mate- 
rially lessen  the   germ  content  of  the    milk. 

Next  to  the  stable,  the  dairy  utensils  are  an  im- 
portant source  of  infection  with  bacteria.  They  be- 
come attached  to  the  seams  and  corners  of  the  ves- 
sels, and  are  not  dislodged  even  with  the  most  careful 
cleaning,  and  when  the  fresh,  warm  milk  is  drawn 
into  such  vessels  the  germs  immediately  begin  to  grow 
and  develop.  The  most  scrupulous  care  must,  of 
course,  be  taken  in  cleaning  any  vessels  in  which 
milk  is  contained,  but  no  vessel  can  be  considered 
safe  so  far  as  conveying  germs  is  concerned  unless 
it  has  been  exposed  to  the  action  of  live  steam  for 
at  least  three  minutes,  and  then  kept  in  a  secure 
place   until   needed   for  use.      With   these   precautions 


78  Milk  mid  Its  Products. 

in  regard  to  the  animal,  milker  and  utensils,  milk 
may  be  secured  with  a  minimum  number  of  bacteria. 
The  difference  in  the  number  of  bacteria  in  milk  so 
drawn,  and  in  milk  carelessly  drawn,  may  easily 
amount  to  a  difference  of  eighteen  to  twenty -four 
hours    in   keeping  quality  under  like  conditions. 

Holding  at  low  temperatures. — If  milk  be  immedi- 
ately cooled  to  a  temperature  of  40°  F.,  or  thereabouts, 
very  little  fermentation  will  go  on,  though  it  will  be 
frequently  found  that  after  three  or  four  days  the 
milk  or  cream  may  have  a  more  or  less  disagreeable 
flavor,  due  to  the  presence  of  some  germs  that  de- 
velop slowly  even  at  low  temperatures.  If  low  tem- 
peratures are  to  be  depended  upon  as  a  means  of 
keeping  fermentations  in  check,  it  is,  of  course,  of 
prime  importance  that  every  precaution  should  have 
been  taken  to  prevent  the  access  of  germs  to  the 
milk  in  the  first  place.  The  fewer  germs  the  milk 
contains  to  begin  with,  the  more  effective  will  low 
temperatures  be  as  a  means  of  preservation.  With 
care  in  both  these  respects,  milk  or  cream  may  be 
kept  in  a  fresh  and  merchantable  condition  for  a 
week   or   ten   days. 

Destruction  of  germs  in  the  milk. — A  large  number 
of  chemical  agents  is  more  or  less  destructive  to 
germ  life.  Many  of  them  are  so  violent  in  their 
action  as  to  destroy  the  milk  as  well  as  the  germs, 
but  there  are  many  which  are  destructive  to  germ 
life,  with  no  effect  upon  the  composition,  odor  or 
flavor  of  the  milk  ;  but  all  of  these  without  excep- 
tion  are   more   or   less   injurious   to   the    human   sys- 


Antiseptics   and   Disinfectants.  79 

tem,  particularly  if  they  are  used  continuously,  even 
though  only  in  small  quantities.  Of  the  compounds 
which  may  be  used  for  this  purpose,  formalin,  saly- 
cilic  and  boracic  acids  and  their  derivatives  are  un- 
doubtedly the  least  injurious,  but  their  use  is  not 
to  be  recommended  under  any  circumstances.  Some 
attempts  have  been  made  to  utilize  the  electric  cur- 
rent as  a  means  of  destroying  germ  life  in  milk  ; 
but  they  have  so  far  proved  ineffectual,  and  in- 
stances are  reported*  where  electrolysis  of  the  milk 
constituents  occurred  where  a  continuous  current  was 
employed.  Heat,  then,  is  the  only  available  agent 
that  can  be  used  for  the  destruction  of  germs  al- 
ready present  in  the  milk.  This  destruction  of  germs 
in  milk  or  any  other  fluid  by  means  of  heat  is  called 
sterilization.  In  order  to  absolutely  sterilize  any  sub- 
stance, it  is  necessary  that  it  should  be  subjected 
to  a  heat  of  212°  to  240°  F.  for  one  hour  on  each 
of  three  successive  days.  This  will  kill  not  only  the 
germs  that  are  in  active  growing  condition,  but  any 
spores  that  may  be  present.  A  lower  temperature, 
175°  to  212°  F.,  will  kill  actively  growing  germs,  but 
even  at  this  temperature  chemical  changes  are  set  up 
in  the  milk  which  give  rise  to  flavors  known  as 
boiled  or  cooked  flavors,  that  are  disagreeable  to  a 
large  number  of  people.  In  order  to  overcome  the 
bad  effects  of  heating  at  such  high  temperatures 
another  process,  known  as  pasteurization,  is  used. 
Pasteurization. — The    name   is   taken  from  Pasteur, 

*LTn4ustri^  Lajtier^,  April  189Q, 


80  MilJc   and   Its   Products. 

who  discovered  and  used  the  process  in  controlling 
the  fermentations  of  wine  and  beer.  It  differs  from 
sterilization  only  in  the  degree  of  heat  used,  and,  in 
fact,  may  be  properly  called  an  incomplete  or  partial 
sterilization.  The  destructive  effect  of  heat  upon 
germ  life  depends  both  upon  the  degree  of  heat  and 
the  length  of  time  to  which  the  germs  are  exposed. 
A  large  number  of  germs  are  killed  at  temperatures 
from  133°  to  140°  F.,  while  others  are  killed  at  tem- 
peratures varying  from  150°  to  165°  F.  These  latter 
temperatures  include  the  germs  of  all  of  the  ordinary 
ferments  and  most  of  the  germs  of  specific  diseases, 
including  that  of  the  tubercle  bacillus.  Since  the 
tubercle  bacillus  is  the  disease  germ  most  likely  to  be 
present,  milk  is  ordinarily  considered  to  be  safe  from 
disease  germs  when  it  has  been  pasteurized  at  a  tem- 
perature sufficiently  high  to  destroy  it.  This  is  a 
temperature  of  149°  F.  for  thirty  minutes,  a  tem- 
perature of  155°  F.  for  fifteen  minutes,  or  a  tempera- 
ture of  167°  F.  for  ten  minutes,  and  these  temperatures 
have  conie  to  be  looked  upon  as  standard  pasteuriz- 
ing temperatures.  Milk  may  be  heated  to  165°  F., 
if  quickly  cooled  afterwards,  without  developing  a 
boiled  taste ;  so  that  it  is  possible  that  milk  be 
rendered  safe  from  the  germs  of  disease  and  free 
from  the  ordinary  germs  of  fermentation  without 
developing  in  it  a  boiled  taste.  But  in  order  to 
pasteurize  milk  safely,  it  is  necessary  that  means 
should  be  provided  for  cooling  rapidly  from  the 
pasteurizing   temperatures   to    50°    F.    or   below. 

Milk  carefully  pasteurized,   as  above  described,  will 


Apparatus  for   Pasteurization.  81 

remain  sweet  thirty -six  to  forty -eight  hours  longer 
at  ordinary  temperatures  than  milk  not  pasteurized, 
from  which  germs  have  been  excluded  with  ordinary 
care. 

The  problem  of  successful  pasteurization,  then, 
depends  upon  the  means  of  raising  the  milk  in  a 
short  time  to  the  required  temperature,  holding  it 
there  uniformly  for  ten  or  twenty  minutes,  and  then 
cooling  it  rapidly  to  50°  or  below.  Several  forms 
of  apparatus  have  been  devised  for  this  purpose. 
Some  of  them  are  fairly  perfect,  but  most  of  them 
are  lacking  in  some  important  point.  With  the  pres- 
ent activity  in  regard  to  this  subject  we  shall  un- 
doubtedly have  in  the  course  of  a  year  or  two,  much 
more  perfect  apparatuses  for  this  purpose  than  are 
at  present  available.  The  perfect  pasteurizing  ma- 
chine should  cover  the  following  points  :  Quick, 
perfect  and  uniform  heating  of  the  milk  ;  perfect 
control  of  the  temperature  ;  quick  and  uniform  cool- 
ing ;  compact  form  ;  ease  of  cleansing ;  absence  of 
pumping  arrangements  ;  security  against  re -infection 
during    the    process. 

Selection  of  milk  for  pasteurization. — For  the  best 
results  in  pasteurizing,  it  is  also  essential  that  the 
milk  be  as  fresh  and  free  from  fermentations  as 
possible.  Russel  and  Farrington  have  found*  that 
milk  that  has  developed  as  much  as  .2  of  1  per 
cent  of  lactic  acid  is  too  sour  for  satisfactory  re- 
sults.       Inasmuch    as    this    amount    of    acid    cannot 


Wisconsin  Agr.   Exp.    Station,   Bulls.   44   and  52. 
F 


82  Milk    and    Its    Products. 

readily  be  detected  b}^  the  senses  of  smell  or  taste, 
Farrington's  alkaline  tablets  offer  a  very  convenient 
means  of  selecting  milks  that  are  suitable  or  un- 
suitable for  pasteurizing  purposes.  For  this  purpose 
it  is  convenient  to  make  the  tablet  solution  (see 
Chap.  VII.)  by  dissolving  one  tablet  in  each  ounce 
of  water,  or  one  tablet  in  30  c.  c.  of  water.  Then 
with  a  cup  or  other  convenient  vessel  and  a  small 
measure  of  any  suitable  size,  the  comparative  acid- 
ity of  different  milks  can  be  readily  and  quickly  de- 
termined as  follows  :  Put  a  measure  full  of  milk 
into  the  cup  and  add  two  measures  of  the  tablet 
solution.  If  the  color  disappears,  more  than  .2  of  1 
per  cent  of  lactic  acid  is  present,  and  the  milk  is  too 
sour  for  pasteurizing  purposes.  If  the  milk  remains 
pink,  less  than  .2  of  1  per  cent  of  lactic  acid  is  pres- 
ent, and  the  milk  may  be  safely  used.  If  it  is 
desirable  to  measure  the  amount  of  acid,  each  meas- 
ure of  solution  may  be  roughly  taken  to  represent 
.1  of  1  per  cent  of  acid.  Thus,  if  the  pink  color 
remains  when  one  measure  of  the  solution  has  been 
added,  the  milk  contains  .1  per  cent  of  acid.  If  it 
require  four  measures  of  the  solution  before  the  pink 
color  is  permanent,  the  milk  contains  A  per  cent  of 
acid.  A  convenient  measure  for  this  purpose  is  made 
by  soldering  a  piece  of  stiff  wire  to  the  side  of  a 
No.  10  cartridge  shell,  after  the  manner  of  a  milk- 
measuring   dipper. 


CHAPTER   V, 

MARKET    MILK. 

In  general,  any  conditions  which  make  milk 
of  better  quality  for  manufacture,  also  make  it  of 
better  quality  to  be  consumed  as  milk.  These 
conditions  are  not  only  those  which  have  to  do  with 
the  composition  of  the  milk,  but  any  other  influences, 
as  feed,  health,  care  of  the  cows,  or  conditions  of 
cleanliness.  Several  conditions  affect  the  quality  of 
milk  intended  for  consumption  as  such.  In  the 
first  place,  it  must  be  of  high  quality  so  far  as 
the  composition  is  concerned.  Second,  it  must  be 
secreted  from  healthy  cows,  fed  on  pure  food  and 
kept  in  clean  stables.  Third,  it  must  be  so  treated 
that  the  fat  does  not  readily  separate  from  the  other 
solids,  and  it  must  not  readily  undergo  fermentation. 
Last  of  all,  it  must  be  clean. 

Cleanliness. — Since  cleanliness  is  equally  impor- 
tant, whether  the  milk  is  intended  for  consumption 
or  manufacture,  it  is  well  to  take  this  up  in  detail 
first.  All  vessels  used  to  contain  milk  should  be 
heavily  tinned  ;  pails,  cans,  and  the  like,  that  are 
of  the  kind  called  ironclad  are  preferable  on  ac- 
count of  durability.  An  efiicient  means  of  attain- 
ing cleanliness  is   in  avoiding  seams    in   the  utensils. 

183) 


84  Milk    and   Its   Products. 

This  is  secured  by  the  use  of  the  pressed  or  seam- 
less vessels  wherever  possible,  and  Avhen  it  is  not 
possible  to  use  these,  by  taking  care  that  the  joints 
are  completely  and  smoothly  filled  with  solder.  In 
ordinary  pails  as  found  in  the  market  this  is  never 
done,  and  it  is  a  matter  of  considerable  importance 
to  the  purchaser  that  all  such  seams  be  resoldered 
before  using.  The  tinware  should  be  kept  bright 
and  perfect.  So  soon  as  any  rust  spots  make  their 
appearance,  an  entrance  is  given  into  the  soft  iron 
for  germs  and  small  particles  of  decaying  matter, 
w^hich  are  in  consequence  removed  with  much  more 
difficult  J'.  Milk  is  much  more  easily  removed  from 
vessels  when  it  has  not  been  allowed  to  become 
dried  upon  their  surface.  If  rinsed  as  soon  as 
emptied,  tin  vessels  may  be  much  more  easily  cleaned 
than  if  allowed  to  stand  for  several  hours.  For 
such  rinsing,  lukewarm  water  is  much  preferable  to 
cold  or  hot  water.  Cold  water  does  not  so  readily 
unite  with  the  milk  as  warm  water,  and  hot  water, 
by  coagulating  the  albumin,  may  cause  the  milk  to 
stick  or  "cook  on"  to  the  sides  of  the  vessel.  The 
process  of  cleaning  vessels  that  have  contained  milk 
should  be  :  First,  to  rinse  them  thoroughly  in  luke- 
warm water ;  second,  to  wash  them  thoroughly  with 
the  aid  of  some  good  soap  or  alkali,  in  water  as 
hot  as  the  hand  will  bear ;  third,  to  thoroughly 
rinse  in  hot  water  ;  fourth,  to  expose  to  live 
steam  from  one  to  two  minutes  ;  fifth,  exposure,  if 
possible,  in  bright  sunlight  from  two  to  three  hours. 
With   these   precautions,  not  only  will  the  tinware  be 


Methods   of  Securing    Clean    Milk.  85 

kept  clean  and  bright,  but  no  germs  will  find  a 
resting  place  in  the  crevices.  The  use  of  much 
strong  alkali  is  inadvisable,  as  it  serves  to  cloud 
and  tarnish  the  tin,  giving  it  a  dull  appearance.  If 
the  vessels  are  exposed  to  steam  until  they  are 
thoroughly  hot,  and  then  placed  in  such  position 
that  they  will  drain,  no  other  drying  will  be  neces- 
sary. 

Having  taken  every  precaution  that  the  vessels 
are  thoroughl}^  cleansed,  the  prevention  of  access 
of  dirt  to  the  milk  in  process  of  milking  is  impor- 
tant. To  this  end,  the  body,  especially  the  lower 
part  of  the  belly  and  udder,  of  the  cow  should  be 
thoroughly  brushed  and  preferably  dampened  just 
before  milking.  The  hands  of  the  milker  should 
be  clean  and  his  clothes  free  from  dust,  and  the 
air  of  the  stable  should  be  free  from  dust.  If 
the  stable  floor  is  dampened,  it  will  not  only  aid 
in  this  respect,  but  in  summer  time  will  materi- 
ally reduce  the  temperature  of  hot  and  overcrowded 
stables.  With  these  precautions,  we  may  expect  to 
secure  milk  containing  a  minimum  amount  of  dirt  ; 
but  with  all  these  precautions,  more  or  less  dirt  will 
find  access  to  it.  And  immediately  after  milk- 
ing, as  much  as  possible  of  this  dirt  should  be 
removed  by  at  once  straining  the  milk  through  a 
brass  wire  strainer  of  not  less  than  fifty  meshes  to 
the  inch  and  three  or  four  thicknesses  of  loosely 
woven  cotton  or  woolen  cloth.  The  cloth  strainer 
not  only  removes  fine  particles  of  dirt,  but  also 
entangles  a  considerable  number  of  germs,  and  hence 


86 


Mill-    and   Its    Producfs. 


these    strainers    should   be    cleansed    with    great    care, 
and   should   be   frequently'   renewed. 

Treatment  after  draiving. —  So  soon  as  the  milk  is 
drawn,  it  should  be  rapidly  brought  to  a  temperature 
slightly  below  the  surrounding  atmosphere.  While  it 
is  being  cooled  it  should  be  stirred  to  prevent  the 
cream  from  rising,  and  in  milk  that  has  been  cooled 
in  this  way  there  will  be  comparatively  little  tendency 
afterward  for  the  cream  to  separate  from  the  milk. 
Milk  so  treated  is  in  an  ideal  condition  for  consump- 
tion, even  though  the  consumer  may  consider  the 
quality  poor  because  of  the  slight  tendency  of  the 
cream  to  form  on  the  surface. 

Aeration  of  milk. — Milk  when  drawn  from  the  cow 
contains  a  certain  amount  of   dissolved  gases.       These 

gases     contain   more    or   less 
of  what  is  known  as  animal 
odor,   the    amount    of     this 
odor  depending  very  largely 
upon  the  physical  condition 
of    the  animal    at    the  time 
the  milk   is   drawn.       Some- 
times   the     amount     is    very 
slight    and    scarcely    notice- 
able, at   other  times  it  is  so 
great  as   to  be  extremely  of- 
fensive.      These    gases    and 
the    accompanying    odor    are 
easily      removed     from     the 

Star"    milk    cooler    and 

aerator.  milk    by    cxposurc    of     the 


Fig.  7 


Good    Influence    of  Aeration. 


87 


milk  to  the  air  during  the  process  of  cooling,  and  to 
this  extent  aeration  of  the  milk  is  an  advantage. 
Various  forms  of  aerators  and  combined  aerators  and 
coolers  have  been  devised,  many  of  which  are  simple 
and  effective,  and  the  best  results  follow  their  use. 
In  order  to  secure  these  results  by 
aeration,  however,  it  is  necessary 
that  the  apparatus  used  for  aeration 
should  expose  the  milk  thoroughly 
to  the  air,  should  not  be  cumber- 
some, and  should  be  simple  and  ea- 
sily cleaned;  moreover,  the  process 
of  aeration  should  always  take  place 
in  the  purest   atmosphere  possible. 

Delivery  of  the  milli.  —  In  ordi- 
nary practice  in  the  smaller  towns 
and  villages,  and  to  a  considerable 
extent  in  the  larger  cities  also,  the 
milk  is  placed  in  cans  in  which  it  is  transported 
from  the  dairy,  and  is  measured  out  in  small  quan- 
tities to  each  customer  from  the  cans  in  which  it  was 
originally  placed.  Where  care  is  taken  to  cool  the 
milk,  as  described,  and  during  the  process  of  serving 
the  customers  to  keep  the  contents  of  the  cans  well 
stirred,  substantial  justice  is  done  each  individual  cus- 
tomer in  the  matter  of  giving  him  the  due  proportion 
of  cream  and  skimmed  milk.  This  has  been  well 
shown  in  a  trial  made  at  the  Cornell  University 
Agricultural   Experiment    Station*   several    years    ago, 


"  Champion '' 
milk  cooler  and  aera- 
tor. 


■Cornell  University  Agricultural  Experiment  Station,  Bulletin  No.  20, 


88 


Milk    and    Its    Products. 


the    interesting   results  of   which  are   quoted   below  in 
full  detail  : 

To  determine  just  how  much  variation  there  is  in  the  fat 
of  milk  served  to  the  different  patrons  of  a  route  by  dipping, 
a  member  of  the  Station  staff  accompanied  a  milkman  as  he 
went  upon  his  route,  and  as  the  milk  was  about  to  be 
served  to  various  patrons,  took  samples  for  analysis.  The 
dipper,  such  as  is  ordinarily  used  by  milkmen,  was  provided 
with  a  long  handle,  so  that  it  rested  on  the  bottom  of  the 
can  when  not  in  use.  The  milk  was  not  stirred  except  by  the 
motion  of  the  wagon  and  the  raising  of  the  dipper.  Twelve 
samples  were  taken,  and  yielded  to  analysis  the  following  per- 
centages   of    fat  : 


No. 


.  4.52) 

.  4.43  y 

4.41  J 

.  4.32) 
.  3.85  y 
.  5.05  J 

1 


4.15 
4.02 
4.05 

4.94 

4.78 
4.85 


Taken  from  Can  A. 


Taken  from  Can  B. 


Taken  from  Can  C. 


Taken  from  Can  D. 


The  milk  was  contained  in  four  30-quart  cans,  marked 
A,    B,    C    and   D.       The    samples    were    taken    as    follows: 

No.  1. — Taken  from  A  at  5.50  a.  m.,  within  a  few  rods 
of    starting. 

No.  2. — Taken  when  the  milk  in  A  was  half  gone,  at 
6.10.  Seventeen  dips  had  been  made  since  No.  1  was  taken, 
and   three-fourths  of  a  mile  traveled. 

No.  3.  — Taken  from  the  bottom  of  A  at  6.20.  Twelve  dips 
had  been  made  since  No.  2  was  taken,  and  three-fourths  of  a 
mile  traveled. 

No.  4.  — Taken  from  the  top  of  B  at  6.10,  three-fourths  of 
a  mile  from  starting. 


Variations  in  Quality  in  Dipping  from  Can: 


89 


No.  5. — Taken  from  tlie  middle  of  B  at  7.20.  Six  quarts 
had  been  added  to  B  at  6.35,  and  two  and  one-fourth  miles 
traveled   between    taking  samples  4  and  5. 

No.  G.  —  Taken  from  the  bottom  of  B  at  7.55.  One  and 
three-quarter   miles    traveled    since    taking    sample    5. 

No.  7.  —Taken  from  the  top  of  C  at  6.20,  one  and  one- 
half   miles    from    the    start. 

No.  8. — Taken  from  the  middle  of  C  at  C.50.  One  mile 
had  been  traveled  since  taking  No.  7.  At  6.35  six  quarts  re- 
maining in  the  bottom  of  A,  and  about  an  equal  quantity 
bought   of    another    dealer,    had   been    added  to   C. 

No.  9. —  Taken  from  the  bottom  of  C  at  7.00.  Fifteen 
dips  had  been  made,  and  a  half  mile  traveled,  since  8  was 
taken. 

No.    10.  — Taken    from  the  top    of  D  at    7.50. 

No.  11. — Taken  from  the  middle  of  D  at  a  time  when 
the  wagon  had  stood  still  for  four  minutes,  with  the  dipper 
resting  on  the  botton  of  the  can.  Time,  8.15,  and  one  mile 
traveled    since    10    was    taken. 

No.    12.  — Taken    from    the    bottom    of    D. 

A   second    and    third   trial    gave    similar    results. 


SECOND 

TRIAL. 

a. 

b. 

Average. 

Sample  1    . 

.    .  4.86 

4.78 

4.82 

Sample  2    . 

.    .  4.71 

4.71 

Sample  3    . 

.    .  4.82 

4.82 

Sample  4    . 

.    .  4.83 

4.74 

4.78 

Sample  5    . 

.    .  4.73 

4.82 

4.77 

THIRD 

TRIAL. 

a. 

b. 

Average 

Sample  1    . 

.      4.20 

4.16 

4.18 

Sample  2    . 

.      4.11 

4.00 

4.05 

Sample  3    . 

.    .  4.13 

4.01 

4.07 

Sample  4    . 

.    .  4.15 

4.04 

4.09 

Sample  5    . 

.      4.01 

4.00 

4.00 

(Before  starting.) 
(Top  of  can.) 
(One-third  gone.) 
(Two -thirds  gone.) 
( Bottom  of  can. ) 


(Top  of  can.) 
(One-fourth  gone.) 
(One -half  gone. ) 
(Three-fourths  gone) 
(Bottom  of  can. ) 


90 


Mill'    and    Its    Products. 


These  results  were  abundantly  confirmed  by  a  sim- 
ilar series  made  by  Dean  in  Canada''^. 

The  removal  of  the  covers  of  the  cans  in  the 
dusty  and  dirty  streets  always  results  in  considerable 
contamination  of  the  milk,  hence  the  practice  of 
putting  the  milk  into  bottles  upon 
the  farm,  and  delivering  these  bot- 
tles intact  to  the  consumer,  has 
rapidlj-  increased  since  its  introduc- 
tion, some  ten  years  ago.  When 
the  bottles  are  used,  the  milk  should 
be  put  into  them  as  soon  as  it  is 
drawn,  strained  and  cooled ;  they 
should  then  be  sealed  and  kept  in  a 
cool  place  until  ready  for  delivery. 
This  method  of  delivery,  although 
it  entails  a  greater  expense  in  outfit 
and  transportation  and  a  consider- 
able loss  from  breakage,  is  much  to 
be  preferred  to  the  old  manner. 
Milk  so    handled,   and   kept  at  a 

Fig.     9.         "Common      ,  .  -,      ,  ,  _o  -,        -^o 

seuse"  milk  shipping  tcmpcraturc  oetweeu  4o  and  ou 
F.,  should  be  in  good  condition 
sixty  hours  after  it  is  drawn.  Its  life  can  be  pro- 
longed by  pasteurization,  and  the  liability  to  trans- 
mission of  diseases  through  the  milk  at  the  same 
time  reduced  to  a  minimum,  but  whether  pasteuriza- 
tion should  be  relied  upon  for  these  purposes  is 
still  somewhat  of  an  open  question.  In  so  far  as 
immunity    from   diseases  which  may  be  present  in  the 


*  Ontario  Agricultural   College,   Bulletin   No.   66. 


RealtJif Illness   of  Shimmed  Milk.  91 

cows  is  coucerned,  official  inspection  of  the  herds 
is  undoubtedly  a  greater  safeguard  than  dependence 
upon  pasteurization  or  sterilization  ;  and  so  far  as 
the  liability  of  transmission  of  other  diseases  is  con- 
cerned, the  milkman  who  is  careless  in  regard  to 
the  cleansing  of  his  utensils  would  quite  as  likely  be 
careless  in  the  pasteurization  or  sterilization  process, 
so  that  reliability  of  the  milkman  is  an  important 
factor  in  the  purity  of  the  milk  supply,  no  matter 
what  other  precautions  are  taken. 

Bad  flavors  in  milk. — Milk  may  be  unfit  for  con- 
sumption for  reasons  other  than  the  presence  of 
dirt  or  infection  with  bacterial  germs.  The  cow 
herself  is  often  responsible  for  bad  flavors  in  milk. 
When  lactation  is  far  advanced  the  milk  often  has 
a  disagreeable  salty  taste.  In  extreme  cases  it  may 
even  be  described  as  acrid  or  bitter.  While  there 
is  nothing  particularly  unwholesome  about  such  milk, 
its  bad  flavor  makes  it  unfit  for  food,  and  if  the 
cow  is  within  two  months  of  calving,  she  should  be 
allowed  to  go  dry  at  once.  If  the  time  before  calv- 
ing is  longer  than  this,  the  bad  flavor  may  often  be 
remedied  by  taking  care  that  the  cow  has  plenty  of 
succulent  food,  as  roots  or  silage,  and  particularly^ 
that  the  proportion  of  dry,  fibrous  food  is  reduced 
to  a  minimum. 

Digestive  disorders  of  any  sort  in  the  cow  are 
frequently  accompanied  by  strong  flavors  in  the 
milk.  These  flavors  are  not  to  be  attributed  to  the 
food,  but  to  the  bad  condition  of  the  animal,  and 
they   normally   tend   to   disappear  when   the    digestive 


92  Milk    and    Its    Products. 

organs  regain  their  tone.  Disorders  of  this  sort 
are  especially  likel}'  to  occur  when  cows  that  have 
been  poorly-  fed  during  the  winter  are  suddenly  turned 
on    fresh    rank    pasture    in    the    spring. 

Quality  of  milk  for  consimii)tion. — The  fat  is  the 
most  variable  and  the  most  valuable  constituent  of 
the  milk,  so  that  milk  is  ordinarily  considered  to  be 
of  value  for  human  food  in  proportion  to  the  amount 
of  fat  it  contains,  but  where  it  is  to  be  used  as 
a  food  in  large  quantities,  the  fat  may  frequently 
be  present  in  too  large  quantities  for  the  digestion 
of  many  persons.  Milk  containing  about  4  per 
cent  of  fat  is  probably  an  ideal  food  for  the  gen- 
eral mass  of  human  beings.  If  there  is  above  5 
per  cent  of  fat  the  other  solids  are  somewhat  out 
of  proportion,  and  many  are  likely  to  have  trouble 
with  their  digestion  from  using  large  amounts  of 
such  milk.  On  the  other  hand,  if  there  is  less 
than  3  per  cent  of  fat,  the  casein  and  other  solids 
are  in  too  great  proportion  to  the  fat,  and  are  less 
readily  digested.  The  question  of  the  healthfulness 
of  milk  from  which  a  large  part  of  the  fat  has  been 
removed  is  one  frequently  discussed.  The  removal  of 
the  fat  does  not  thereby  in  any  way  injure  the  other 
solids ;  they  are  still  there,  and  still  as  useful  for 
food  as  before  the  fat  was  removed,  only  in  con- 
suming such  milk  as  food  the  fat  must  be  supplied 
in  some  other  way.  For  the  person  of  vigorous 
digestion,  who  for  reasons  of  economy  desires  to 
supply  the  fat  required  by  his  system  in  some 
cheaper  form  than  that  of  milk  fat,  skimmed  milk  is 


Legal    Standards  for  Milk.  93 

a  wholesome  and  nutritious  article  of  diet,  which 
furnishes  to  the  system  almost  the  same  sort  of 
nutrients  that  lean  meat,  eggs,  or  foods  of  like  na- 
ture do,  and  no  one  should  be  debarred  by  legisla- 
tive or  municipal  enactment  from  using  such  an 
article   of   food   if   he   so   desires. 

Control  of  milk  su]32)lij . — Since  milk  is  so  extremely 
variable  in  quality,  and  is  so  easily  adulterated ; 
since  often  considerable  variations  are  not  readily 
detected ;  above  all,  because  the  amount  of  milk 
used  by  any  given  person  or  family  is  compara- 
tively small,  the  consumer  of  milk  is  almost 
wholly  at  the  mercy  of  the  producer  and  dealer,  and 
must  rely  for  a  good  product  very  largely  upon  their 
honor.  The  state  has  recognized  this;  and  to  pre- 
vent imposition  by  unscrupulous  people,  has  in 
various  ways  sought  to  regulate  the  sale  of  milk  and 
like  products.  The  chief  means  used  has  been  to 
establish  arbitrary  standards  of  quality,  and  to  subject 
to  fine  those  dealers  whose  goods  should  be  found 
to  be  below  the  required  standard.  The  standards 
established  by  various  states  and  municipalities  have 
varied  widely.  From  2.5  to  3.7  per  cent  of  fat, 
and  from  11.5  to  13  per  cent  of  total  solids,  have 
been  the  minimum  requirements.  (See  Appendix  C.) 
These  standards,  while  efficient  in  securing  honest 
dealing  where  they  are  rigidly  enforced,  nevertheless 
may  work  injustice,  so  far  as  the  honesty  of  the 
dealer  is  concerned,  under  various  circumstances,  and 
may  prevent  the  production  and  sale  of  a  compara- 
tively low  quality  product  at  a  reasonable  price.      It 


94  Milk   and    Its   Products. 

would  seem,  therefore,  that  the  best  means  of  regulat- 
ing the  traffic  in  milk  would  be,  not  to  set  up  an 
artificial  standard  to  which  all  must  come,  but  to 
require  each  individual  dealer  to  guarantee  his  own 
standard,  and  hold  him  responsible  if  his  milk  were 
found  below.  In  this  waj'  it  would  be  possible  to 
sell  milk  of  various  qualities,  from  strictlj^  skimmed 
to  heavy  cream,  upon  a  graduated  scale  of  prices, 
with    exact   justice    to    every   one. 

Cream  for  consuniption. — Since  the  introduction  of 
the  centrifugal  separator,  the  use  of  cream  as  an 
article  of  diet  and  for  household  purposes  has  very 
rapidly  increased,  and  the  amount  of  cream  so  used 
now  represents  a  very  considerable  proportion  of  the 
total  production  of  milk.  The  sale  of  cream  to  con- 
sumers is  usually  carried  on  in  connection  with  the 
sale  of  milk,  and  the  conditions  of  care  and  cleanli- 
ness necessary  in  the  one  case  apply  equally  well  to 
the  other.  Cream,  however,  is  much  more  generally 
delivered  in  bottles  than  is  milk,  and  since  the  daily 
quantity  used  is  smaller,  there  is  a  greater  demand 
that  it  should  keep  sweet  for  a  longer  time.  For-  this 
reason  it  is  still  more  important  that  cream  should  be 
kept,  so  far  as  possible,  free  from  contamination  with 
germs  of  fermentation,  and  at  a  comparatively  low 
temperature  from  the  time  it  leaves  the  separator 
till  it  goes  into  the  consumer's  hands;  and  of  course 
the  fresher  and  freer  from  germs  the  milk  is  when 
separated,  the  better  will  be  the  keeping  qualities  of 
the  resulting  cream.  Milk  containing  more  than  .2  per 
sent  of   lactic   acid   should   not   be  used   for  the    pro- 


Cream  for   Consumption.  95 

duction  of  cream  for  commercial  purposes.  With 
care  it  is  not  difficult  to  produce  cream  that  will 
remain  sweet  for  four  or  five  days  or  even  a  week. 

Pasteurized  cream. — For  the  sake  of  its  better  keep- 
ing qualities  cream  that  is  to  be  used  for  commercial 
purposes  is  often  pasteurized.  If  it  is  pasteurized  at 
155°  F.  for  10  minutes  and  quickly  cooled  to  50°  F. 
or  below,  and  bottled  in  sterile  bottles,  it  will  keep, 
with  ordinary  precautions,  for  a  week  or  more. 
Cream  so  pasteurized  will  have  no  perceptibly  cooked 
taste,  but  it  will  be  considerably  thinner  in  consist- 
ency than  cream  of  a  like  percentage  of  fat  that 
has  not  been  pasteurized,  because  the  pasteurization 
greatly  and  permanently  reduces  the  viscosity.  Ow- 
ing to  the  fact  that  the  "quality"  or  richness  of  the 
cream  in  fat  is,  in  popular  estimation,  almost  wholly 
in  proportion  to  its  consistency,  this  lack  of  con- 
sistency in  pasteurized  cream  is  a  matter  of  consid- 
erable commercial  importance.  Babcock  and  Russel* 
have  shown  that  the  consistency  may  be  restored 
by  the  addition  of  a  small  amount  of  a  solution 
of  lime  in  cane  sugar,  to  which  they  have  given 
the  name  viscogen.  The  amount  added  is  so  small 
(about  1  part  to  150  of  cream)  that,  while  the  con- 
sistency is  perfectly  restored,  the  cream  is  not 
affected  in  odor,  taste  or  composition  ;  but  since 
the  addition  of  anything  whatever  to  milk  or  cream 
is  prohibited  in  many  states,  cream  to  which  vis- 
cogen has  been  added  should  always  be  sold  under 
a  distinctive  name,  as  visco- cream.  For  preparation 
of   viscogen,  see   Appendix   A. 

*Wisconsin  Agricultural   Experiment   Station,  13th   Report,  p.  81. 


96  MilJc    and    Its    Products. 

Quality  of  cream. —  The  most  unsatisfactory  thing 
about  the  sale  of  cream,  commercially,  is  its  varying 
percentage  of  fat.  Since  cream  is  merely  milk  into 
which  a  greater  or  less  proportion  of  fat  has  been 
gathered,  it  follows  that  cream  may  be  anything 
that  the  seller  can  induce  the  puehaser  to  accept 
under  that  name,  and  maj^  contain  anywhere  from  6 
or  8  up  to  60  or  70  per  cent  of  fat.  Where  cream 
is  raised  by  the  gravity  process  it  will  contain  from 
18  to  22  per  cent  of  fat ;  but  where  it  is  separated 
by  centrifugal  process  the  separator  can  be  so 
adjusted  as  to  take  cream  of  almost  any  fat  con- 
tent desired.  Since  cream  is  almost  universally  sold 
without  any  guarantee  as  to  fat  content,  the  con- 
sumer has  constantly  demanded  a  richer  and  richer 
cream  till,  in  some  places,  cream  containing  less  than 
40  per  cent  of  fat  can  scarcely  be  sold,  though  a 
moderately  rich  cream  is  quite  as  useful  for  table 
and  domestic  purposes.  The  high  price  that  must  be 
had  for  the  extremely  rich  cream  also  operates  to 
check  consumption.  Evidently,  then,  it  would  be  to 
the  advantage  of  both  seller  and  consumer  if  cream 
were  always  sold  upon  a  guaranteed  fat  content,  with 
the  price  adjusted  to  varying  percentages  of  fat;  but 
as  yet  little  has  been  done  in  this  direction,  or  even 
in  the  way  of  establishing  an  artificial  standard  for 
cream.  In  Iowa  cream  must  contain  at  least  15  per 
cent  of  fat  and  in  Minnesota  and  the  District  of 
Columbia  it  must  contain  20  per  cent.  In  all  other 
places  cream  may  be  anything  that  can  be  sold  as 
such. 


CHAPTER   VI. 

SEPARATION   OF   CBEAM. 

Cream  is  that  part  of  milk  into  which  a  large 
portion  of  its  fat  has  been  gathered.  It  is  com- 
posed of  the  same  constituents  as  milk,  but  they 
are  not  in  the  same  or  any  constant  relative  pro- 
portion. Cream  is  separated  from  milk  to  be  con- 
sumed as  food,  and,  as  a  matter  of  convenience,  in 
the  manufacture  of  butter.  The  separation  of  cream 
is  always  attended  with  some  loss  of  fat.  The  per- 
centage of  fat  in  cream  may  vary  anywhere  between 
8  and  70  per  cent.  Cream  of  good  quality  for  com- 
mercial purposes  should  contain  from  18  to  25  per 
cent  of  fat,  and  very  rich  cream  contains  from  35  to 
40  per  cent  of  fat.  Cream  is  composed  of  glob- 
ules of  fat,  with  such  part  of  the  water  and  solids 
as  adhere  to  them.  Its  separation  from  the  milk 
is  effected  by  means  of  the  difference  in  specific 
gravity  between  the  globules  of  fat  and  the  milk 
serum.  The  fat  in  the  milk  is  in  the  condition 
known  as  an  emulsion  ;  that  is,  in  the  form  of  minute 
globules,  which  are  kept  from  running  together  and 
coalescing  by  means  of  the  surface  tension  of  their 
particles  and  the  viscosity  of  the  liquid  in  which 
they     float ;     therefore,    any    condition    of     the    milk 

G  (97) 


98  Milk    and    Its    Products. 

which  tends  to  increase  the  surface  tension  or  the 
viscosity  will  act  as  a  hindrance  towards  the  sepa- 
ration of  the  cream.  While  the  viscosity  of  the  milk 
serum  prevents  the  particles  of  fat  from  uniting 
into  a  mass,  still  the  particles  have  considerable  free- 
dom of  movement  in  the  milk,  and  being  of  a  less 
specific  gravity,  of  course  are  acted  upon  with  less 
intensity  by  any  force  to  which  the  milk  is  subjected. 
If  the  milk  is  allowed  to  remain  at  rest  in  a 
vessel,  the  force  of  gravity,  acting  with  different  in- 
tensities upon  the  globules  of  fat  and  the  milk  serum, 
will  cause  the  particles  of  fat  to  gather  together 
near  the  surface  of  the  liquid.  In  so  gathering, 
they  carry  with  them  certain  of  the  milk  con- 
stituents, and  the  layer  of  fat  globules  and  adher- 
ing particles  we  call  cream.  From  time  immemo- 
rial, and  until  within  a  very  recent  date,  the 
force  of  gravity,  acting  in  the  way  indicated,  has 
been  the  only  means  used  for  separating  cream  from 
milk.  Now  machines  are  in  use  that  effect  a  sepa- 
ration of  the  cream  from  milk  by  means  of  centrif- 
ugal force,  and  at  the  present  time  we  have  three 
systems  of  separating  cream  ;  namely,  by  gravity 
acting  upon  a  thin  layer  of  milk  in  a  shallow  vessel, 
known  as  the  Shallow  Pan  System ;  secondly,  by 
gravity  acting  upon  a  deeper  mass  of  milk,  usually 
submerged  or  partially  submerged  in  water,  known 
as  the  Deep  Setting  System ;  and  thirdly,  by  ma- 
chines making  use  of  centrifugal  force,  known  as 
the  Centrifugal  or  Separator  System.  The  quality 
of    the    cream    for    consumption   or    for    purposes   of 


Systems   of  Separating    Cream.  99 

manufacture  is  not  affected  either  one  way  or  the 
other  by  any  of  these  three  systems,  so  that  their 
relative  economy  rests  wholly  upon  the  complete- 
ness, cost  and  ease  of  separation. 

Since  the  separation  of  cream  from  milk  is  al- 
ways attended  with  some  loss  of  fat,  it  is  pertinent 
to  inquire  as  to  the  necessity  of  any  separation  of 
the  cream  when  butter  is  to  be  made.  It  is  per- 
fectly possible  to  manufacture  butter  directly,  by 
churning  whole  milk  without  separating  cream,  and 
undoubtedly  the  first  churns  were  skins  of  animals, 
into  which  the  whole  milk  was  placed  and  then 
agitated  until  the  butter  was  brought  ;  but  under 
good  conditions  it  is  not  possible  to  so  complertely 
remove  the  fat  from  the  milk  by  a  churning  process 
as  by  a  creaming  process ;  so  that  while  there  is 
some  loss  in  separating  the  cream,  there  is  usually 
a  greater  loss  in  churning  the  butter  from  the  whole 
milk.  Even  when  the  loss  of  fat  in  the  butter- 
milk is  no  greater  than  the  loss  of  fat  in  the 
skimmed  milk,  the  greater  amount  of  labor  required 
to  churn  the  whole  mass  of  milk  still  renders  cream- 
ing an  economical  practice  in  the  manufacture  of 
butter. 

Gravity  creaming. — In  separating  cream  by  force 
of  gravity,  there  is  a  greater  loss  of  fat,  a  longer 
time  required,  and  the  various  conditions  affecting 
the  milk  have  a  greater  influence  upon  the  creaming 
than  when  centrifugal  separation  is  used.  The 
conditions  of  the  milk  that  affect  the  creaming  by 
the  gravity  process  are :     First,  the    size   of  the    fat 


100  Milk   and   Its    Products. 

globules ;  second,  the  amount  of  solids  not  fat  in 
the  milk  ;  third,  the  character  of  the  solids  not 
fat.  The  larger  the  fat  globules  the  more  readily 
they  separate  from  the  milk,  since  the  larger  the 
sphere  the  less  the  ratio  between  the  surface  and 
the  mass,  so  that  a  large  fat  globule  meets  with  pro- 
portionately less  resistance  because  of  the  viscosity 
of  the  milk  than  a  small  one.  The  size  of  the  fat 
globules  is  to  a  great  extent  a  characteristic  of  the 
breed  and  individuality  of  the  animal,  but  cows 
newly  calved  secrete  larger  fat  globules  than  those 
in  advanced  periods  of  lactation  ;  consequently  we 
find  that  the  milk  from  new  milch  cows  is  more 
readily  creamed  than  from  those  long  in  milk. 
The  amount  of  solids  not  fat  affects  creaming  by 
the  gravity  process  because  of  the  difference  it  effects 
in  the  specific  gravity  of  the  fat  and  milk  serum. 
The  solids  not  fat  are  all  heavier  than  water,  and 
in  the  milk  are  in  a  state  of  solution  or  semi -solu- 
tion ;  hence,  an  increase  in  the  amount  of  solids  not 
fat  increases  the  specific  gravity  of  the  milk  serum 
in  which  they  are  dissolved,  and  makes  the  differ- 
ence between  the  specific  gravity  of  the  fat  and 
milk  serum  greater  and  the  separation  of  the  fat 
easier.  The  proportion  of  solids  not  fat  is  in- 
fluenced by  the  period  of  lactation  and,  to  a  con- 
siderable extent,  by  the  character  of  the  food.  Cows 
far  advanced  in  lactation  often  give  milk  extremely 
rich  in  solids  not  fat.  Cows  fed  on  diy  food  give 
milk  containing  less  water  than  those  fed  on  watery 
or   succulent    foods.       In   so   far   as   these   conditions 


Gravity   Processes   of  Creaming.  101 

increase  the  amount  of  solids  not  fat,  we  should  ex- 
pect such  milk  to  be  more  easily  creamed,  but  the 
favorable  effect  of  the  increase  of  solids  is  more 
than  counterbalanced  by  the  unfavorable  effect  of 
the  character  of  the  solids.  Of  the  solids  not  fat, 
albumin,  casein,  sugar  and  ash  increase  the  viscos- 
ity of  the  milk  in  the  order  named,  and  of  these 
the  casein  is  more  subject  to  variation,  so  that  the 
increase  in  the  proportion  of  solids  not  fat  ordi- 
narily means  an  increase  in  casein,  and  this  means 
a  largely  increased  viscosity.  And  the  increase  in 
viscosity  tends  to  prevent  the  separation  of  the  fat 
more  than  the  increase  in  specific  gravity  tends  to 
aid  it.  In  general,  the  conditions  which  bring  about 
an  increase  in  the  viscosity  of  the  milk  occur  at  the 
same  time  as  the  fat  globules  are  growing  smaller,  so 
that  we  find  a  wide  range  of  variability  in  the  ease 
and  completeness  with  which  cream  may  be  separated 
by  gravity  process. 

Shallow  pan  crea7ning .—This  is  the  oldest  method 
of  separating  cream  from  milk,  and  notwithstanding 
the  rapid  changes  that  have  taken  place  in  cream- 
ing methods  since  the  introduction  of  centrifugal 
separators,  large  amounts  of  butter  are  still  made 
from  cream  separated  in  this  way.  The  conditions 
most  favorable  for  a  complete  separation  of  the  fat 
in  the  shallow  pan  system  are,  that  the  milk  should 
be  put  at  rest  in  the  pans  as  quickly  as  possible 
after  it  is  drawn,  that  it  should  cool  with  a  fair  de- 
gree of  rapidity  to  a  temperature  of  60°  F.,  and  that 
it  should   remain  as  nearly  as  may    be   constantly   at 


102  Milk    and   Its    Products. 

that  temperature  for  at  least  thii-ty-six  hours. 
Further,  since  the  milk  must  remain  for  so  long  a 
time,  it  is  essential  that  the  atmosphere  to  which  it 
is  exposed  be  pure  and  free  from  currents  of  air 
and  particles  of  dust.  These  conditions  can  be 
secured  in  a  clean,  cool,  well  ventilated  cellar. 
In  the  shallow  pan  system,  the  depth  of  milk  should 
be  from  2  to  4  inches.  Occasionally  water,  usually 
running  water,  is  used  to  secure  a  quick  cooling 
and  more  even  temperature  surrounding  the  milk, 
and  when  this  is  done  the  depth  of  the  milk  may 
be  increased  to  4  or  6  inches.  Under  the  shallow 
pan  system,  the  cream  is  separated  from  the  milk 
by  removing  it  from  the  surface  with  a  thin  flat 
instrument,  usually  made  of  tin,  and  called  a 
skimmer.  In  this  method  of  removal,  it  is  not 
possible  to  completely  remove  all  the  cream  that  has 
risen  to  the  surface,  and  in  removing  the  cream 
more  or  less  of  the  milk  is  taken  with  it,  so  that 
in  the  process  of  skimming  there  is  a  considerable 
loss  of  fat  and  a  thin  cream  is  always  obtained ; 
but  even  if  the  losses  in  the  skimming  operation 
could  be  obviated,  the  separation  of  the  particles  of 
fat  in  the  shallow  pan  system  is  less  complete  than 
in  either  of  the  others.  Under  ordinarily  good  con- 
ditions, 20  per  cent  of  the  fat  in  the  milk  is  lost 
when  the  shallow  pan  system  is  used.  Skimmed  milk 
containing  less  than  .5  of  1  per  cent  of  fat  is 
rarely  obtained  under  this  system. 

Beep  setting  system. — About  thirty  years  ago  it 
was  discovered  that  if  milk  could  be  set  in  vessels 
when    first   drawn,  and  rapidly    cooled    to  a  tempera- 


Theorij   of  Beep    Setting   System.  103 

ture  of   about   40°    F.,  and   held   at   that   temperature 
for    twelve    to    twenty  -  four     hours,    not    only   could 
the   depth   be  increased  from  4  to  20  inches,  but  the 
separation     was    much    more    complete    in     a    shorter 
time.       In   order   to   bring   about   quick   cooling,  ves- 
sels not  more  than  a  foot  in  diameter  were  used,  and 
water,   either    from    cold    springs    or    containing    ice, 
was   used   as   the   refrigerant.       Two    essentials,  then, 
for  complete  creaming    by    this  system  are    the  rapid 
and    immediate   cooling   of   the   milk   to   40°    F.,  and 
a    sufficient    supply   of    ice    to  maintain   this    tempera- 
ture    for     twenty  -  four    hours.       Under   these     condi- 
tions  the    fat   may    be    so    completely   separated    that 
not   more  than  .2  of    1    per  cent  of   fat   is  left   in  the 
skimmed    milk.       Various     devices     have    been    used, 
the   best   known   of   which   is   the    Cooley    system,    in 
which     the    cans    are    not    only    surrounded    by    ice- 
cold     water,    but     completely     submerged     in    it,    the 
chief   effect   of    the    submerging    being    to    guard    the 
milk   against    contamination   through    the   atmosphere. 
The  same  conditions  as   to   the   character  of   the   milk 
affect   completeness  of   separation   in  both    the  shallow 
pan    and     deep    setting    systems,    but    no    completely 
satisfactory   explanation   has   ever   been  assigned   as  a 
reason     why     the     fat     globules     should     rise     more 
rapidly    and    more    completely    through    20   inches    of 
milk  at  a   temperature  of    40°  F.   in   the  deep   setting 
system,    than   through   4   inches    at    a   temperature    of 
60° -70°  F.  in  the  shallow  pan  system. 

It  has  been  asserted  that  because  water  is  a 
better  conductor  of  heat  than  fat,  it  will  cool  more 
rapidly    than    the    fat,   and   will    increase    in   density 


104  Milk    and   Its    Products. 

till  its  maximum  density  is  reached  at  about  40°  F,, 
at  which  temperature  the  difference  between  the 
specific  gravity  of  the  water  or  milk  serum  and  the 
fat  will  be  at  its  greatest,  and  the  separation  of  the 
fat  for  that  reason  promoted.  But  while  the  water 
does  cool  faster  than  the  fat,  the  fat  shrinks  or 
increases  in  density  much  faster  than  the  water, 
so  that  the  difference  in  specific  gravity  between  the 
two  is  no  greater,  and  in  fact  less,  at  low  tempera- 
tures than  at  high  ones.  Further,  the  viscosity  of 
the  milk  serum  is  much  increased  at  low  tempera- 
tures, so  that  the  favorable  influence  of  low  tempera- 
tures cannot  be  explained  upon  these  grounds. 
Arnold*  attempted  to  explain  the  favorable  influence 
wholly  upon  the  relative  contraction  of  the  fat  and 
serum,  as  follows  : 

Water  is  a  better  conductor  of  heat  than  fat  ;  hence  when 
the  temperature  of  milk  varies  either  up  or  down,  the  water 
in  the  milk  feels  the  effect  of  heat  or  cold  sooner  than  the 
fat  in  the  cream  does,  therefore  the  cream  is  always  a  little 
behind  the  water  in  swelling  with  heat  or  shrinking  with  cold, 
thus  diminishing  the  difference  between  the  specific  gravity  of 
the  milk  and  cream  when  the  temperature  is  rising,  and  in- 
creasing   it   when    the    temperature    is    falling. 

But   that    this    explanation    is   not    sufficient,    Bab- 
cock  t    has    shown  thus  : 

Though  it  is  true  that  water  is  a  better  conductor  of  heat 
than  fat,  the  small  size  of  the  fat  globules  renders  it  impossible 
that,  under  any  circumstances,  there  can  be  more  than  a  small 
fraction  of  a  degree  difference  between  the  temperature  of  the 
fat  and  that  of  the  milk  serum.  Moreover,  within  the  limits 
of  temperature    practical    for   creaming    (90°  F.  to  40°  F.),    the 

•American  Dairying,  p.  210. 

t Wisconsin  AgricultTiral  Experiment  Station,  Bull.  18,  p.  24, 


Effect   of  Fibrin.  105 

coefficient  of  expansion  of  butter  fat  is  more  than  three  times  as 
great  as  that  of  water,  so  that  in  order  to  maintain  the  same 
relative  difference  in  their  specific  gravities,  when  the  tempera- 
ture is  falling,  the  milk  serum  must  cool  more  than  three  times 
as  rapidly  as  the  fat.  In  other  words,  when  the  milk  serum  has 
cooled  from  90°  F.  to  40°  F.,  or  through  50°,  the  fat  globules 
should  have  lost  less  than  17°,  and  should  still  have  a  tempera- 
ture of  over  73°  F.,  a  difference  between  the  temperature  of  the 
fat  and  serum  of  more  than  33°.  Such  a  condition  is  mani- 
festly impossible,  but  any  less  difference  than  this  would  cause 
the  fat  to  become  relatively  heavier  than  at  first,  and  would 
operate  against  the  creaming. 

On  the  whole,  the  most  satisfactory  explanation  of 
the  good  effect  of  the  low  temperature  in  the  deep 
setting  system  is  that  advanced  by  Babcock,*  that 
the  presence  of  fibrin  in  milk,  especially  when  it  has 
coagulated  in  the  form  of  threadlike  masses,  permeat- 
ing the  fluid  in  all  directions,  offers  a  considerable 
obstacle  to  the  rising  of  the  fat  globules.  The  sudden 
reduction  of  the  temperature  quickly  after  the  milk 
is  drawn,  by  preventing  the  formation  of  these 
fibrin  clots  or  threads,  aids  in  the  separation  of  the 
fat.  This  would  be  entirely  satisfactory  were  it  not 
for  the  fact  that  it  has  been  shown  that  while  it 
is  usually  of  advantage  to  cool  the  milk  imme- 
diately after  it  is  drawn,  in  some  cases,  at  least, 
the  setting  and  cooling  may  have  been  delayed  for 
a  time  long  enough  to  permit  the  formation  of 
fibrin  clots  without  appreciable  effects  upon  the  sep- 
aration, as  the  following  tables  t  very  clearly  show, 
the  efficiency  of  creaming  being  measured  by  the 
percentage  of  fat  in  the  skimmed   milk: 

*Loc.  cit. 

t  Cornell  University  Agriciiltural  Experiment  Station,  Bull.  No.  29,  p.  73. 


106 


Milk   and   Its    Products. 


Effect   of  delayed   setting   upon   creaming. 


1 

o 

i 

P. 

a 

1 
.2 

1 

h 
1^ 

I. 
Set  at  once. 

Date, 
1890. 

a 

p. 

•2d 

11 

1    Dec.  24,  p.  M.  .    .    . 

2.  Dec.  25,  a.  m.  .    .    . 

3.  Dec.  25,  p.  m.  .    .    . 

4.  Dec.  26,  a.  m.  .    .    . 

5.  Dec.  26,  p.  M.  .    .    . 

6.  Dec.  26,  A.  M.  .    .    . 

7.  Dec.  26,  p.  M.  .    .    . 

8.  Dec.  27,  a.  M.  .    .    . 

13 

8.5 
12 

9.75 
16 

8.25 
14 

9 

40 
40 
40 
40 
40 
40 
40 
40 

3.90 
3.45 

4.05 

4.1.0 
4.15 
4.00 
3.90 

.35.5 

18.5 
37 
29 
36 

92 
86 
86 
88 
90 

.57 
.56 
.59 
.55 
.24 

.A.verage  of  all    .... 
Average  Nos.  1-5  ..    . 

11 

40 

3.94 

88 

.50 
.50 

11 

III. 

Delayed— kept  warm. 

Delayed— cooled. 

'O* 

s.ii 

-d 

GM 

Date, 
1890. 

CO 

1 

7i 

1 
p. 

a 

11 

a 

CO 

1 
'3 

"5 

1 
p. 

a 

^a 

il 

ZB 

p 

c 

» 

0/^ 

2 

S 

EH 

d^-S 

J 

S 

H 

A^-S 

1.  Dec.  24,  P.  M. 

24.5 

60 

88 

.59 

30 

60 

68 

.64 

2.  Dec.  25,  a.  m. 

18.5 

45 

84 

.56 

75.5 

220 

62 

.55 

3.  Dec.  25,  p.  m. 

37 

45 

84 

.47 

61.5 

60 

74 

.53 

4.  Dec.  26,  a.  m. 

30.25 

130 

82 

.68 

5.  Dec.  26,  p.  m. 

36 

75 

90 

.22 

6.  Dec.  26,  a.  m. 

37.5 

205 

92 

.68 

37.5 

205 

58 

.66 

7.  Dec.  26,  p.  m. 

24 

90 

90 

.49 

23.5 

90 

65 

.65 

8.  Dec.  27,  a.  m. 

74 

210 

95 

.68 

74 

210 

64 

.51 

Average  of  all     . 

107 

88 

.55 

141 

65 

.59 

Average  Nos.  1-5 

.50 

.57 

Average    "     6-8 

.58 

.60 

Effect  of  Delay  in  Deep   Setting  System.        107 

The  milk  was  divided  into  three  portions  ;  one  was  set  at 
once,  one  was  delayed  for  an  hour,  but  kept  up  to  a  tempera- 
ture of  92  in  a  water  bath,  and  the  third  was  put  in  the  open 
air  and  allowed  to  cool  for  an  hour  before  set.  In  the  cases 
of  delay,  the  milk  was  stirred  up  just  before  it  was  placed  in 
the  creamer,  and  all  the  settings  were  made  in  Cooley  cans,  in 
ice  water. 

The  trials  reported  under  the  same  number,  with  the  excep- 
tion of  the  first  and  second,  are  comparable,  as  they  were  made 
from  different  portions  of  the  same  samples  of  milk.  In  num- 
bers 1  to  5,  inclusive,  the  delayed  sample  (Column  II.)  was 
kept  warm  in  a  water  bath  ;  in  numbers  6  to  8  the  milk 
used  had  been  carried  about  on  the  route,  and  the  delayed 
sample  was  heated  up  after   having  been  allowed  to  cool. 

From  a  similar  series  of  experiments  Jordan* 
concluded : 

That  with  herds  of  ordinary  size,  it  will  not  be  profitable 
to  submit  to  any  great  inconvenience  in  order  to  place  the 
milk  in  ice  water  immediately  after  it  is  drawn.  In  a  half 
hour  to  an  hour,  milk  does  not  seem  to  cool  sufficiently  to  ma- 
terially affect  the  completeness  with  which    cream  will    rise. 

In  order  to  overcome  certain  difficulties  that  often 
occur  in  raising*  cream  by  deep  setting  process,  dilu- 
tion of  the  milk  with  water  has  been  recommended, 
usually  under  one  of  the  three  following  conditions: 

1st.  Dilution  with  one -fourth  to  one -third  of  hot 
water,  135°  F.,  and  setting  in  deep  cans  at  a  tem- 
perature as  low  as  can  be  obtained  without  the  use 
of   ice,  not   below  55°. 

2d.    Dilution  with  one -half   to  equal   quantities  of 


*  Maine  Agr.  Exp.  Sta.  Kept.  1890,  Part  II.  page 


108  Milk    and   Its    Products. 

cold  water,  and  setting  under  the  same  conditions  as 
above. 

Both  of  these  being  intended  as  substitutes  for  the 
use  of   ice  in  cool  deep  setting  in   the  summer  time. 

3d.  Dilution  with  one -third  to  one -fourth  of  hot 
water  (135°),  setting  in  deep  cans  in  ice  water  (40  F.). 

This  last  intended  to  overcome  the  difficulty  of 
complete  creaming  often  found  in  the  fall  and  early 
w^inter  with  the  milk  of  cows  far  advanced  in  the 
period  of   lactation. 

The  idea  is  that  the  increased  fluidity  imparted  to 
the  milk  by  the  water  would  facilitate  the  separa- 
tion of  the  fat  globules.  During  the  winters  of 
1888-9  and  1889-90  very  little  ice  could  be  harvested 
through  the  dairy  regions  of  the  northeastern  United 
States,  and  in  the  summer  following  this  idea  of 
dilution  was  widely  advocated  and  considerably  prac- 
ticed ;  but  experience  and  experiment*  have  shown 
that  while  dilution  may  be  of  some  advantage  when, 
for  lack  of  a  supply  of  ice  or  other  reasons,  it  is 
not  possible  to  secure  a  temperature  below  60°  F., 
it  can  in  no  case  be  considered  a  satisfactory  sub- 
stitute for  setting  the  cans  in  water  at  a  tempera- 
ture  of   40°  F. 

The  amount  of  advantage  which  may  be  obtained 
where  dilution  is  practiced,  as  measured  by  the  per- 
centage of  fat  in  the  skimmed  milk,  is  seen  in  the 
following  tables  (on  pages  109  and  110),  taken  from 
Bulletin  No.  39  of  the  Cornell  University  Agricultural 
Experiment    Station : 

*  Vermont  Agricultural  Experiment  Station,  4th  Ann.  Rept.  p.  100. 


Effect  of  Dilution  in  Beep  Setting  System.      109 


Diluted   and   undiluted   millc    set    in  water   at   a    temperature 
of  60°   F. 


i 

i 

Temperatures  F. 

4 

a 

'2 
a 
a 

S 

Diluted. 

Not  diluted. 

Date, 

1892. 

M 
% 

1 

1 

•Sd 
3  a 

P.. 

11 

is 

Feb.  19  . 
"   19  . 

54 

72 

18 

84 
84 

135 

97 
84 

65 
65 

60 
59 

12 
13 

4.2 
4.2 

1.07 

.89 

1.33 

1.09 

"   22  . 
"   22  . 

54 
72 

18 

90 
90 

136 

99 
90 

64 
64 

59.5 
57.5 

12.5 
14.5 

4.2 

4.2 

.52 

.43 

.97 

.77 

"   23  . 
"   23  . 

72 

18 

89 
89 

135 

101 
89 

66 
66 

60.75 
58.50 

11.25 
13.5 

4.3 

4.3 

.80 

.68 

1.12 

.91 

"   28  . 
"   28  . 

54 
72 

18 

88 
88 

134 

98 

88 

57 
57 

58 
57 

14 
15 

.35 

.28 

.65 

.51 

"   29  . 
"   29  . 

54 
72 

18 

86 
86 

134 

97 
86 

60 
60 

59.75 
58 

12.25 
14 

4.4 
4.4 

.68 

.56 

1.18 

.95 

Mar.  1  . 
1  . 

54 

72 

18 

86 
86 

135 

m 

86 

60 
60 

61 

58.5 

11 
13.5 

4.1 
4.1 

.68 

.58 

.96 

.78 

"   13  . 
"   13  . 

54 
72 

18 

86 
86 

135 

96 
86 

60 
60 

60.75 
57.75 

11.25 
14.25 

4.3 
4.3 

.85 

.72 

.82 

.66 

"   14  . 
"   14  . 

27 
36 

9 

84 

84 

136 

96 

84 

58 
58 

29.5 
30 

6.5 
6 

3.9 
3.9 

.88 

1^ 

1.14 

.95 

"   15  . 
"   15  . 

27 
36 

9 

86 
86 

132 

95 
86 

58 
58 

30 
29.5 

6 
6.5 

3.9 
3.9 

.73 

.61 

1.25 

1.02 

"   26  . 

"   27  . 

27 
b6 

9 

88 
88 

136 

101 
88 

56 
56 

29.5 

28.5 

6.5 
7.5 

1-1 

.67 

.53 

"   27  . 
"   27  . 

54 
36 

18 

90 
90 

135 

100 
90 

64 
64 

60.25 
30 

11.75 
6 

4.5 
4.5 

.81 

.68 

.70 

.58 

"   28  . 
"   28  . 

27 
36 

9 

88 
88 

136 

102 

88 

61 
61 

31 

30 

5 
6 

4 
4 

1.21 

1.01 

"   31  . 
"   31  . 

27 
36 

9 

87 
87 

135 

102 

87 

62 
62 

30 
29.75 

6 
6.25 

4.1 
4.1 

.93 

.78 

1.17 

.97 

Apr.   2  . 
^'        2  . 

27 
36 

9 

91 
91 

135 

103 
91 

65 
65 

30 
29 

6 

7 

4.7 
4.7 

1.08 

.90 

1.68 

1.35 

4  . 
4  . 

27 
36 

9 

92 
92 

135 

102 
92 

62 
62 

29 
29 

7 
7 

4.2 
4.2 

.31 

.25 

.92 

.74 

Average 

■ 

.76 

.62 

1.05 

.85 

110 


Milk    and   Its    Products. 


Diluted  and  undiluted  milk  set   in  ivater  at  a    temperature  of 
40°-45°  F. 


Temperatures  P. 

1 

Diluted. 

Not  diluted. 

n  • 

U 

c  J 

li 

Date, 

1892. 

1 

i 

M 

u 

1 

1 
'a 

i 

"21 
II 

13S 
a  E 

5B 

i 

^ 

i 

^ 

CO 

I 

1 

r 

u  ■^ 

^ 

^a 

I' 

Feb.  20 

54 

18 

87 

140 

100 

44 

58 

14 

4.4 

.32 

.26 

"  20  . 

72 

87 

87 

44 

54.25 

17.75 

4.4 

.25 

.19 

"  21  . 

54 

18 

88 

136 

99 

44 

57.5 

14.5 

4.4 

.20 

.16 

"  21 

72 

88 

88 

44 

53.75 

18.25 

4.4 

.24 

.18 

"  24  . 

54 

18 

87 

134 

97 

45 

56.25 

15.75 

4.2 

.23 

.18 

"  24  . 

72 

87 

87 

45 

53.5 

18.5 

4.2 

tl7 

.13 

"  25  . 

M 

18 

90 

134 

100 

46 

57 

15 

4.4 

.23 

.1,8 

"  25  . 

72 

90 

90 

46 

54.25 

17.75 

4.4 

.26 

.20 

Mar.  30 

27 

9 

86 

135 

100 

44 

29 

7 

.32 

.26 

"  30 

36 

86 

86 

44 

27 

9 

.35 

.26 

"  17  . 

27 

9 

88 

136 

97 

44 

29 

7 

4.7 

.11 

.09 

"  17  • 

18 

88 

88 

44 

13.5 

4.5 

4.7 

.18 

.14 

"  30  . 

27 

9 

86 

135  !  100 

44 

28 

8 

5 

.08 

.06 

"  30  . 

18 

86 

86 

44 

13 

5 

5 

.12 

.09 

Aprils  . 

27 

9 

90 

138 

103 

46 

29.75 

6.25 

3.3 

.31 

.25 

^'   5  . 

18 

90 

90 

46 

14.5 

3.5 

3.3 

.28 

.23 

Average 

.23 

.18 

|.23 

.18 

Summing  up  all  of  the  experiments,  the  average 
efficiency  of  creaming  as  measured  by  the  percent- 
age of  fat  in  the  skimmed  milk  would  appear  to  be 
about  as  follows  : 

Diluted,  set    at    60°  (39  trials)     .77  per  cent. 
Undiluted,  set  at  60°  (30      "    )  1.00       " 
"    "  40°  (26      "    )     .29       " 
It     would    seem,  therefore,  that     while,  when    the 
milk  is  set  at   60°  F.  or  thereabouts,  there  is  consider 
able  advantage,  so   far   as   the   efficiency   of   creaming 


Dilution    Separator.  Ill 

is  concerned,  in  diluting  it  with  25  per  cent  of  warm 
water,  this  dilution  cannot  be  regarded  as  a  sub- 
stitute for  setting  without  dilution  in  ice  water,  and 
it  has  the  further  disadvantage  of  requiring  increased 
tank  capacity. 

About  1897  the  idea  that  dilution  with  water  is 
an  important  aid  in  gravity -creaming  broke  out  with 
renewed  activity.  It  was  especially  recommended  by 
the  manufacturers  of  certain  forms  of  cheap  tin  cans 
in  which  dilution  was  recommended  as  an  essential 
part  of  the  process.  These  cans  were  called  gravity 
"separators"  modified  by  various  high-sounding, 
qualifying  phrases,  with  the  evident  intention  of  con- 
veying the  idea  that  this  process  was  as  efficient  as 
centrifugal  separation,  and  large  numbers  of  the 
"separators"  have  been  sold,  mainly  to  unsuspecting 
or  ignorant  farmers,  who  have  been  deluded  into  the 
idea  that  they  were  securing  a  contrivance  equal  in 
efficiency  to  a  centrifugal  separator  at  a  small  frac- 
tion of  the  cost.  The  form  of  many  of  the  cans  was 
patented,  but  it  was  soon  shown*  that  so  far  as  the 
process  is  concerned,  the  patents  were  valueless,  and 
trials  at  several  experiment  stations  showed  that  dilu- 
tion in  gravity  separators,  of  whatever  form,  is  no 
more  efficacious  than  has  been  shown  above.  For 
this  reason,  and  because  rival  manufacturers  have 
become  involved  in  controversies  over  their  various 
patents,  the  "dilution  separator  boom"  is,  fortunately, 
likely  to   be   of    short   duration. 

Centrifugal  separation.  —  The  invention,  develop- 
ment and  perfection  of    the  centrifugal  separator  has 

♦Cornell  University  Agricultural  Experiment  Station,  Bulls.  151  and  171. 


112  Milk   and    Its  Products. 

been  the  chief  factor  iu  revolutionizing  methods  of 
butter- making.  By  its  greater  efficiency  it  has  pre- 
vented otherwise  unavoidable  losses,  and  b}'  its  greater 
economy  of  labor  it  has  rendered  possible  the  devel- 
opment of  a  profitable  industry  in  many  localities 
Tvhere  it  would   have  been  otherwise  impossible. 

In  separating  cream  in  a  centrifugal  machine,  the 
centrifugal  force  generated  in  a  rapidly  revolving 
bowl  is  made  to  take  the  place  of  the  force  of  grav- 
ity acting  upon  the  milk  at  rest  in  a  vessel.  The 
amount  of  force  generated  is  so  much  greater  than 
the  force  of  gravity  that  the  separation  of  the  par- 
ticles of  fat  is  much  more  rapid  and  much  more 
complete.  The  force,  however,  acts  in  a  horizontal 
instead  of  a  vertical  direction.  In  1877,  a  patent  was 
granted  to  Le  Feldt  &  Lentsch  for  a  machine  to  sepa- 
rate milk  by  centrifugal  force.  This  first  centrifugal 
separator  consisted  merely  of  a  series  of  buckets  hung 
upon  arms  swinging  from  a  central  axis.  When  the 
machine  was  at  rest  the  buckets  assumed  a  vertical 
position,  but  in  motion  they  were  thrown  out  horizon- 
tally from  the  arms.  The  milk  was  placed  in  these 
buckets,  the  machine  set  in  motion  until  the  cream 
was  separated  from  the  skimmed  milk,  and  when  the 
machine  was  allowed  to  come  to  a  stand- still  the 
buckets  assumed  a  vertical  position,  and  the  cream 
was  removed  from  the  top  in  the  same  way  that  it 
was  skimmed  from  any  other  vessel.  From  this  was 
evolved  a  machine  consisting  of  a  revolving  bowl 
or  drum  in  which  the  separation  takes  place,  with 
arrangements    for   removing    the    skimmed    milk    and 


structure    of    Centrifugal    Separator. 


113 


cream  without  stopping  the  machine,  thus  making 
the  separation  continuous.  The  various  parts  of 
the  machine  have  been  much  improved  in  minor  de- 
tails.      At    the    present    time    the   essential    parts    of 

u 


Fig.  10.     Section  of  separator  bowl  of  plain  or  "  Hollow  Bowl  "  type. 

a  separator  are  the  bowl,  with  or  without  internal 
devices  or  arrangements  to  assist  in  the  separation 
of  the  cream  from  the  milk,  an  outlet  for  the 
skimmed  milk,  an  outlet  for  the  cream,  an  inflow  for 
the   whole   milk,   and    the    proper    mechanical    means 

H 


114  Milk   and   Its    Products. 

for  revolving  the  bowl.  (The  more  common  types  of 
separator  l)owls  are  shown  in  Figs.  10-13.)  Usually 
the  bowl  is  driven  in  an  upright  position,  but  there 
are  separators  in  which  the  bowl  is  driven  in  a  hori- 
zontal position,  and  in  the  greater  number  of  ma- 
chines the  walls  of  the  bowl  are  cylindrical.  In  the 
process  of  separation  the  milk  flows  into  the  bowl, 
and,  partaking  of  the  centrifugal  force,  is  forced  to 
the  extreme  outer  edge  of  the  bowl.  As  the  milk 
continues  to  flow  in,  the  bowl  begins  to  fill  from 
the  outside  toward  the  center.  The  centrifugal  force 
acting  more  strongly  upon  those  parts  of  the  milk 
which  have  the  greatest  specific  gravity,  they  are 
thrown  to  the  extreme  outside,  and  the  lighter  por- 
tions, the  fat  globules,  with  whatever  may  adhere 
to  them,  are  forced  to  the  center.  Attached  to  the 
extreme  outer  edge  of  the  bowl  are  one  or  more 
tubes,  which,  bending  inward  along  the  side  of  the 
bowl,  find  an  opening  near  the  center.  These  are 
the  outlets  for  the  skimmed  milk.  From  the  ex- 
treme center  of  the  bowl,  also  leading  to  the  out- 
side, is  the  cream  outlet.  When  the  bowl  becomes 
filled  with  milk,  the  centrifugal  pressure  will  force 
out  through  the  skimmed  milk  outlets  the  milk  nearest 
the  outside  of  the  bowl.  These  outlets  are  made 
of  such  size  in  comparison  with  the  size  of  the  bowl, 
the  speed  of  the  machine,  and  the  size  of  the  inflow 
tube,  that  they  have  a  capacity  of  discharging  the 
milk  from  .4  to  .9  as  fast  as  it  runs  in  ;  the  remain- 
ing contents  of  the  bowl  are  then  forced  toward 
the    center,    and     find    an    exit     through    the     cream 


Theory  of   Centrifugal    Separation.  115 

outlet.  In  this  way  the  milk  as  it  enters  is  divided 
into  two  portions  :  one,  the  larger,  drawn  from  the 
extreme  outer  portion  of  the  bowl,  consisting  of 
skimmed  milk,  and  the  other,  the  smaller,  escaping 
from  the  center  of  the  bowl,  the  cream.  A  third 
portion  also  usually  accompanies  centrifugal  sepa- 
ration. A  part  of  the  semi -solid  constituents  of 
the  milk,  being  heavier  than  the  milk  serum,  are 
thrown  to  the  outside  of  the  bowl,  and  adhere  to 
the  walls  in  the  form  of  a  creamy  or  gelatinous  mass, 
which  is  ordinarily  called  separator  slime.  It  consists 
mainly  of  albuminous  matters  with  some  fat  globules 
adhering,  and  any  particles  of  dirt  or  foreign  mat- 
ter that  maj'  be  mechanically  mixed  with  the  milk. 
It  varies  greatly  at  different  times  and  seasons. 
Usually  the  amount  is  not  large,  but  not  infrequently 
it  is  sufficient  to  clog  the  outlets  of  the  separator  after 
a  run  of  an  hour  or  two.  The  separator  slime  is 
largely  composed  of  matter  deleterious  to  the  qual- 
ity of  cream  and  butter,  and  its  removal  is  to  a 
great  extent  a  purification  of  the  cream.  The  various 
conditions  affecting  this  operation  are  as  follows  : 

Conditions  affecting  the  completeness  of  separa- 
tion.— The  completeness  of  the  separation  is  depend- 
ent upon  the  centrifugal  force  generated,  the  rate 
of  inflow,  the  temperature  of  the  milk,  and  the 
physical  condition  of  the  milk. 

The  amount  of  centrifugal  force  generated  depends 
upon  the  diameter  of  the  bowl  and  the  velocity  of 
rotation . 

Roughly  speaking,   the    centrifugal   force    increases 


116  Milk   and   Its    Products. 

directly  in  proportion  as  the  diameter  is  increased  and 
directly  with  the  square  of  the  velocity.  The  larger 
the  bowl,  then,  and  the  greater  the  speed,  the  greater 
the  centrifugal  force  and  the  more  complete  the  sep- 
aration. The  rate  of  inflow  of  milk  affects  the 
separation,  because  the  separation  is  more  complete 
the  longer  the  milk  is  subjected  to  the  centrifugal 
force,  and  the  slower  the  milk  flows  into  a  given- 
sized  bowl  the  longer  any  particle  will  be  in  flowing 
through  it  and  the  more  completely  will  the  cream 
be  separated.  The  temperature  of  the  milk  affects 
the  fluidity  of  the  fat  globules  and  their  ease  of  mo- 
tion upon  the  other  particles  of  the  milk;  the  warmer 
the  milk  the  more  easily  are  they  separated.  A 
temperature  of  76°  to  98°  F.  is  the  one  commonly 
employed  because  of  the  effect  upon  the  texture  of 
the  butter.  It  is  desirable  that  the  milk  should  be 
separated  at  as  low  a  temperature  as  possible  without 
interfering  with  the  completeness  of  the  separation, 
so  that,  other  things  being  equal,  that  separator  is  the 
best  that  separates  the  milk  at  the  lowest  tempera- 
ture. The  physical  condition  of  the  milk  affects 
separation  by  the  centrifugal  in  the  same  ways  that 
gravity  creaming  is  affected,  but  to  a  ver}^  much 
slighter  degree.  Small- sized  fat  globules,  viscosity 
of  the  milk,  and  coagulation  of  part  of  the  casein 
by  incipient  fermentations,  all  tend  to  make  separa- 
tion more  difficult  ;  but  in  a  majority  of  cases,  un- 
less the  milk  is  so  sour  as  to  be  coagulated,  it  may 
be  completely  creamed  with  a  centrifugal  separator, 
but    will   require  a   slower  feeding  (a  reduction  of    10 


Relative  Amount  Skimmed  Milk  and  Cream.      117 

to  15  per  cent  will  usually  suffice),  aud  a  higher  speed 
of  the  bowl,  or  both. 

Conditions  affecting  the  relative  amount  of  skimmed 
milk  and  cream. —  The  relative  amount  of  skimmed 
milk  and  cream  is  affected  by  the  rate  of  inflow, 
by  the  speed  of  the  bowl,  by  various  special  con- 
trivances upon  the  machines  themselves,  and  to  a 
slight  extent  by  the  temperature  of  the  milk.  In 
the  ordinary  machine  the  size  of  the  skimmed  milk 
outlet  is  fixed,  and  therefore  at  a  given  velocity  the 
outlet  will  discharge  a  nearly  uniform  quantity  of 
fluid.  If,  then,  the  milk  is  turned  into  the  bowl  at 
such  a  rate  that  .8  of  it  escapes  through  the  skimmed 
milk  outlet,  we  shall  have  .8  skimmed  milk  and 
.2  cream.  If  now  we  reduce  the  rate  of  inflow 
by  .1,  we  shall  get  just  as  much  skimmed  milk  as 
before,  but  only  one -half  as  much  cream  ;  or  if  the 
inflow  is  increased  by  .1,  we  shall  get  the  same 
amount  of  skimmed  milk  and  once  and  a  half  as 
much  cream.  If  under  the  first  conditions  all  of  the 
fat  was  gathered  into  the  cream,  we  shall  have  just 
as  complete  a  separation  as  before,  but  will  simply 
get  a  cream  containing  a  greater  or  less  percentage 
of  fat,  provided  that  the  increase  of  inflow  has  not 
increased  the  total  amount  above  the  capacity  of  the 
machine.  In  other  words,  the  greater  the  inflow, 
the  more  cream  and  the  thinner  the  cream ;  the 
smaller  the  inflow,  the  less  cream  and  the  richer  the 
cream.  These  variations  can  only  take  place  within 
comparatively  narrow  limits.  If  we  increase  the  in- 
flow  too   much,  we  shall    soon  reach  a  point  at  which 


118  Milk    and   Its    Products. 

the  milk  passes  so  rapidly  through  the  machine  that 
the  separation  is  not  complete,  and  if  we  reduce  the 
inflow  to  such  a  point  that  the  skimmed  milk  outlet 
has  a  capacity  of  discharging  the  milk  as  fast  as  it 
flows  in,  we  shall  get  a  separation  until  the  bowl 
l)ecomes  filled,  and  then  all  of  the  milk  will  pass 
out  of  the  skimmed  milk  outlet  in  the  same  condi- 
tion in  which  it  enters  the  machine. 

The  speed  of  the  machine,  also,  affects  the  rela- 
tive amount  of  cream  and  its  percentage  of  fat.  The 
size  of  the  skimmed  milk  outlet  being  fixed,  the 
faster  the  bowl  is  revolved  the  greater  the  capacity 
of  this  outlet  will  be,  so  that,  the  rate  of  inflow 
remaining  uniform,  the  faster  the  bowl  is  revolved 
the  less  proportional  amount  of  cream  we  shall  have, 
and  the  richer  it  will  be  in  fat,  and  vice  versa.  It 
must  be  borne  in  mind,  further,  that  the  speed  of 
the  bowl  is  also  an  important  factor  in  the  complete- 
ness of  separation,  and  that  if  the  speed  is  slackened 
in  order  to  get  a  greater  bulk  of  cream,  there  will 
be    danger   of   incomplete    separation. 

Most  of  the  machines  have  arrangements  for  reg- 
ulating the  relative  amount  of  skimmed  milk  and 
cream  without  changing  the  rate  of  inflov*^  or  the 
speed  of  the  machine.  In  most  of  the  machines 
this  arrangement  is  known  as  a  "cream  screw,"  and 
affects  the  amount  of  cream  by  placing  the  cream 
outlet  nearer  or  farther  from  the  center  of  the  bowl; 
the  nearer  the  center  the  cream  screw  is  turned,  the 
thicker  will  be  the  cream  and  the  smaller  the  amount. 
Some    of   the    separators    change    the    proportion    of 


Modifications   in    Structure   of  Bowl. 


119 


cream  by  increasing  or  decreasing  the  capacity  of  tlie 
skimmed  milk  outlet.  If  the  capacity  of  the  skim- 
med milk  outlet  be  decreased,  necessarily  the  amount 
of  the  cream  will  be  increased,   and  vice  versa. 

The  temperature  of  the  milk  only  slig'htly  affects 
the  proportion  of  skimmed  milk  and  cream.  The 
warmer  the  milk,  the  more  fluid  it  is,  and  the  faster 
it  will  pass  through  the  various  openings  of  the  ma- 
chine. Slightly  more  milk  at  85°  will  run  through 
the  same  inflow  than  at  70°,  and  a  large  part  of 
this  increase  will  be  found  in  the  cream.  The 
pressure  of  the  milk  in 
the  vat  above  the  ma- 
chine will  materially  af- 
fect the  rate  of  inflow, 
and  a  few  inches  will 
make  a  difference  of 
two  or  three  hundred 
pounds  per  hour  on 
large -sized  machine. 

Contrivances  in  the 
howl  to  increase  tJie  ef- 
ficiency of  separation . — 
In  the  first  separators 
made,  the  bowl  was 
hollow,  and  the  separa- 
tion was  caused  directly 
by  the  centrifugal  pres- 
sure acting  upon  the 
milk   in    a    mass.       In 

ji         1    J.  1   •  Fig.  11.       Section  of   septarator   bowl  of 

the   later  machines,  va-       ^    the  disc  or  "Aipila"  tj-pe. 


120 


Mill-   and   Its   Products. 


rious  contrivances  have  been  introduced  in  the  bowl 
to  aid  in  the  completeness  of  the  separation  or  to 
increase  the  capacity.  These  contrivances  have  been 
of  two  general  types  :  one  to  break  up  the  wall  of 
milk,  and  so  give  the  particles  of  milk  and  cream 
a  better  chance  to  pass  by  one  another  in  their 
passage  from  the  center  to  the  outside  of  the  bowl; 
the   other,    a    series   of    interruptions    to    the    passage 

of  the  milk  from 
its  entrance 
at  the  c  e  n  t  e  r 
to  the  outside, 
causing  it  to 
travel  a  much 
greater  dis- 
tance and  be 
subjected  to  the 
tj^  centrifugal  force 
for  a  longer 
time.  These 
contriva  n  ces, 
while  adding  to 
the  complexity 
of  the  machine, 
have  increased 
the  capacity 
a  n  d  the  e  ffi- 
ciency  of  the 
separation.  The  best  known  of  these  contrivances 
are  the  so-called  "Alpha"  discs  or  plates, — a  series 
of  cup -shaped   plates,    nearly   filling   the   bowl   of  the 


Fig.  12.     Section    of  separator  bowl  of  "United 
States  ■'  type. 


Mechanical  Conditions  Affecting  Separation.      121 

separator.       These    Alpha    plates    nearly     double    the 
separating   capacity   of   the   hollow   bowl   of  the   same 


Fig.  13.      Parts  of  bowl  of  "United  States  "  type. 


diameter,   and    at  the  same  time  the   efficiency  of  sep- 
aration   is    increased. 

Mechanical  conditions  ivMch  affect  separation. — Cer- 
tain peculiarities  in  the  construction  or  operation  of 
the  machine  often  materially  influence  the  efficiency 
of  separation.  One  of  the  most  important  of  these 
is  that  the  bowl  should  run  steadily  and  smoothly, 
without  any  perceptible  jar  or  trembling.  The  trem- 
bling of  the  bowl  may  be  caused  by  lack  of  per- 
fect balancing  in  the  bowl  itself.  This  can  only  be 
remedied  by  the  manufacturer.       The  bowl  may  trem- 


'122  Mill'    and   Its    Products. 

ble,  also,  because  the  bearings  are  not  perfecth'  ad- 
justed ;  and,  lastly,  the  bowl  may  tremble  because 
the  machine  is  not  set  level  or  upon  a  solid  founda- 
tion. A  second  cause  of  inefficient  separation  is 
variation  in  the  velocity  of  the  bowl.  It  is  quite  as 
important  that  the  bowl  run  uniformly  as  it  is  that 
it  attain  any  given  rate  of  velocity.  In  this  re- 
spect the  turbine  separators  are  more  likely  to  be 
at  fault  than  those  run  by  belt  power,  and  separa- 
tors turned  l\v  hand  are  more  subject  to  variations 
than    those  run    l)y  power. 

An  engine  of  ample  power,  with  a  good  gover- 
nor, and  the  power  transmitted  through  an  interme- 
diate rope  belt  kept  perfectly  tightened,  with  well-oiled 
bearings  all  around,  are  the  best  safeguards  to  uni- 
form speed. 

Efficiency  of  separation  in  centrifugal  machines. — 
With  the  centrifugal  separator  run  under  perfect  con- 
ditions, there  is  still  a  slight  loss  of  fat  in  the 
skimmed  milk.  This  need  not  be  greater  than  .1 
of  1  per  cent.  At  the  present  time  it  is  considered 
that  where  more  than  .1  of  1  per  cent  of  fat  is  left 
in  skimmed  milk,  a  centrifugal  machine  is  not  doing 
perfect  w^ork,  and  numerous  trials  have  shown  that 
the  machines  of  the  leading  forms  can  be  made  to 
reach  this  point  of  efficiency,  as  may  be  seen  from 
the  following  table,  "^  giving  the  average  of  a  large 
number  of  tests  made  by  several  agricultural  experi- 
ment stations  : 

♦Cornell  University  Agricultural  Experiment   Station,   Bulletin  No.   105. 


Relative  Efficiency  of  Separators. 


123 


Per  cent  of  fat  in  skimmed  milk. 

Average. 

Name  of  machine. 

By  series. 

Of  all 
trials. 

Minimum. 

Maximum. 

Accumulator            .    • 

.12 

.11 

.01 

.20 

Alexandra  Jumbo   .    . 

.22 

.22 

.15 

.33 

Columbia       •    ■ 

.09 

.12 

.05 

.34 

Danish  Weston    .    .    . 

.10 

.08 

.01 

.25 

DeLaval 

.13 

.09 

.01 

.50 

Sharpies    ... 
United  States  .... 

.27 
.18 

.16 
.12 

.05 
.01 

.65 
.60 

Victoria 

.21 

.16 

.05 

.38 

A  series  of  trials  made  in  Germany  '■'  shows  a  con- 
siderable variation  in  the  varions  styles,  and,  on  the 
whole,  a  rather  less  efficiency  than  has  been  obtained 
in   this    country,    as   is    seen   in   the   table   following: 


Revolutions 

Pounds 

Tempera- 

Per cent 
of  fat  in 

Number 

Name  of  machine. 

per  min- 
ute. 

separated 
per  hour. 

ture  of 
milk  F. 

skimmed 
milk. 

of  trials. 

Alpha  B     ■    •    • 

5,100 

537 

92 

.23 

37 

Alpha  Baby  .    . 

6,900 

286 

72 

.23 

23 

Baby 

6,360 

129 

88 

.18 

15 

Victoria  . 

.    . 

205 

92 

.17 

19 

Small  Danish  . 

7,241 

288 

90 

.28 

16 

Large  Danish  . 

7,217 

411 

91 

.35 

16 

Adjustable  .  .    . 

8,640 

363 

70 

.10 

3 
26 

Arnold's    .    .    . 

8,531 

458 

90 

.28 

Medium  Brown 

4,037 

268 

91 

.37 

16 

But  while  all  the  forms  of  separators  can  be  made 
to    do   perfect   work,    there   is   more   or   less  variation 


*  Milch  Zeitung,  xxiii.,  p.  296. 


124 


Milk   and   Its    Products. 


in  the  work  done  by  the  different  machines  of  the 
same  style  and  manufacture.  This  variation  is  due 
to  slight  peculiarities  in  the  construction  of  the  in- 
dividual bowls,  and  which  cannot  be  detected  by 
the  ordinary  senses,  and  only  appear  upon  an  ex- 
amination of  the  skimmed  milk  after  actual  use. 
These  differences  are  well  illustrated  in  a  series  of 
trials  made  in  different  factories,*  and  shown  in 
detail  in    the   following   tables: 


ALEX^iNDRA   JUMBO. 

Bated  capacity,  2,000  pounds  per  hour. 


Average 

Pounds 

No. 

of 

Average 

Range 

speed  of 

Range 

sepa- 

Per cent 

Date. 

of 

milk 

of 

bowl, 

of 

rated 

of  fat  in 

fac- 

in whole 

ature. 

temper- 1  revolu- 

speed. 

per 

skimmed 

tory. 

run. 

ature.    tionsper 
minute. 

7,000-7,400 

hour. 

milk. 

Aug.  19. 

7 

3,809 

70 

66-75 

7,200 

1,344 

.25 

"     20. 

8 

70 

68-72 

6,985 

6,800-7,200 

1,170 

.15 

"     20. 

8 

70 

68-72 

6,585 

6,300-6,900 

1,611 

.20 

"     21. 

9 

5,928 

75 

72-81 

6,900 

6,600-7,100 

1,882 

.20 

"     23. 

11 

4,052 

84     1    80-86 

6,600 

6,200-7,400 

1,814 

.33 

Average 

74 

6,854 



1,564 

03 

DE    LAVAL,  ALPHA  NO.  1. 

Bated  capacity,  2,500  pounds  per  hour. 


July  17. 

3 

2,519 

80 

78-85 

5,520 

4,800-6,100 

2,606 

.08 

Aug.  18. 

6 

3,629 

74 

73-76 

5,806 

5,700-6,000 

2,592 

.05 

Sep.  16. 
'^   20. 

17 

1,187 

72 

71-73 

5,933 

5,800-6,000 

2,456 

.08 

22 

4,627 

82 

80-83 

6,071 

5,800-6,200 

2,501 

.04 

"     21. 

23 

6,376 

78 

77-80 

6,044 

6,000-6,200     2,500 

.03 

Oct.    4. 

24 

5,588 

82 

78-85 

5,844 

5,600-6,000,     2,747 

.13 

"      4. 

25 

1,802 

86 

85-90 

6,280 

6,000-6,400     2,040 

.03 

Average 

79 

5,928 

2,491 

06 

'Cornell  University  Agricultural  Experiment  Station,  Bulletin  No.  105. 


Variations  in   Machines  of  Same    Style.         125 


DE     LAVAL,     BABY. 

Bated  capacity,  No.  2,  350;  No.  3,  600  pounds  per  hour 


Date. 

No. 
of 
fac- 
tory. 

Pounds 

of 

milk  in 

whole 

run. 

Average 
temper- 
ature. 

Range 
of 

temper- 
ature. 

Average 
speed  of 
bowl, 
revolu- 
tions per 
minute. 

Range 

of 
speed. 

Pounds 
separ- 
ated 
per 
hour. 

Per  cent 

of  fat  in 

skimmed 

milk. 

1 
14 
19 

205 
146 

96 

83 

81-86 

Rev.  crank 
54 
46 
46 

362 
303 

.05 
.06 
.16 

May  31. 



18. 

Average 

90 

49 



333 

.09 

DE     LAVAL,      STANDARD. 

Bated  capacity,   1,100  pounds  per  hour. 


Sep.  19. 
'^    19. 
"     19. 

21 
21 
21 

— 

73 
73 
72 

71-75 
71-75 
71-75 

Rev.  bowl 
7,914 
8,140 
8,300 

7,700-8,200 
7,600-8,400 
8,000-8,500 

1,020 

930 

1,000 

.25 
.15 
.16 

Average 

73 

8,118 

983 

.19 

SHARPLES     RUSSIAN. 

Bated  capacity,   Standard,   1,100  pounds ;   Imperial, 
per 


2,000  pounds 


hour. 


July  16. 

2 



84 

83-87 

7,775 

7,700-7,900 

2,100 

.40 

July  16. 

2 



88 

87-88 

7,183 

7,000-7,500 

2,130 

.65 

Aug.  17. 

5 

1,718 

80 

78-82 

7,800 

7,700-7,900 

1,874 

.10 

Aug.  24. 

12 

4,028 

81 

80-82 

7,700 

7,100-8,300 

1,033 

.05 

Sept.  14. 

13 

2,509 

85 

84-86 

7,433 

6,800-7,600 

1,158 

.13 

Sept.  17. 

18 

3,562 

87 

82-95 

7,558 

7,200-7,900 

1,752 

.45 

Oct.      6. 

18 

2,716 

90 

87-91 

7,675 

7,400-7,900 

1,873 

.38 

Average 

.    .    .    . 

85 

7,589 

1,703 

.31 

UNITED    STATES. 

Bated  capacity,  2,000  pounds  per  hour. 




July  18. 
Aug.  22. 
Sept.  15. 
Sept.  15. 
Sept.  18. 

4 
10 
15 
16 
20 

83 

81 
94 

88 
78 

82-84 

79-91 

90-98 

80-100 

77-80 

7,120 
7,025 
7,600 
6,075 
6,.586 

7,000-7,200 
6,800-7,300 
7,200-8,000 
5,600-6,600 
6,400-6,800 

2,220 
1,964 
1,403 
1,650 
2.176 

18 

3,962 
1,870 
3,850 
2,902 

.25 
.08 
.38 
.60 

Average 

....        85 

6,881 

1,883 

.30 

126  Milk    and   Its    Products. 

These  slight  diflferences  in  individual  bowls  are 
common  to  all  of  the  different  kinds  of  machines,  so 
far  as  is  known,  and  this  being  the  case,  it  is  al- 
waj'S  due  to  the  purchaser  that  he  should  s<^cure  from 
the  manufacturer  a  guarantee  that  any  given  ma- 
chine will   do  work   of   a    certain    grade  of  efficiency. 

Other  desirable  and  undesirahle  features  of  a  sepa- 
rator.— Other  things  being  equal,  that  separator  is  the 
best  which  will  skim  clean  at  the  lowest  temperature 
and  with  the  least  number  of  revolutions  per  min- 
ute. Other  details  of  construction  being  equally 
good,  and  the  capacities  being  the  same,  that  separator 
will  run  the  easiest  whose  diameter  is  least.  A  ma- 
chine of  small  diameter  not  only  runs  easier,  but  is 
less  easily  thrown  out  of  balance.  The  cream  should 
be  delivered  in  a  smooth  stream  of  uniform  densitj^ 
and  the  cream  outlet  should  be  of  such  form  that 
a  heavy  cream  may  pass  through  it  without  danger 
of  clogging.  The  bowl  should  be  so  constructed  that 
all  parts  may  be  readily  reached  Avith  the  hand  and 
thoroughly   and    easily   cleaned. 


CHAPTER    VII. 

TEE   RIPENING    OF   CREAM. 

By  the  ripening  process  is  meant  all  the  treatment 
which  the  cream  receives  from  the  time  that  it  is  sep- 
arated from  the  milk  nntil  it  is  put  into  the  churn. 
Upon  this  treatment,  and  the  changes  that  the  cream 
undergoes,  very  largely  depend  the  quality  of  the  butter 
as  regards  texture  and  flavor.  The  texture  of  the 
butter  is  very  largely  influenced  by  the  changes  of  tem- 
perature that  are  brought  about  during  the  ripening 
process.  It  seems  to  be  essential  to  the  production  of 
a  firm,  solid  texture  in  the  butter  that  the  cream,  at 
some  time  during  the  ripening  process,  should  be  sub- 
jected to  a  constant  temperature  below  50°  F.  for  sev- 
eral hours.  When  cream  has  been  separated  by  a 
gravity  process,  particularly  by  a  "deep  setting"  one, 
it  has  already  experienced  the  effects  of  such  a  tem- 
perature, and  is  read}^  for  ripening  as  soon  as  re- 
moved from  the  milk.  But  when  cream  is  separated 
by  a  centrifugal  separator,  the  temperature  as  it  comes 
from  the  separator  is  rather  high,  and  butter  of  good 
texture  cannot  be  made  unless  the  cream  is  cooled 
down  and  held  cool  for  several  hours  before  ripening 
has  far  advanced.  The  first  step,  then,  in  the  ripen- 
ing   process  with    separator    cream    is    to    reduce    its 

(127) 


128  Milk  and  Its  Products. 

temperature  as  rapidly  and  as  uniformly  as  possible 
to  at  least  50°  F.,  and  to  hold  it  there  for  as  long 
a  time  as  is  convenient,  usually  six  to  eight  hours. 
Another  point  which  influences  the  texture  of  the 
butter  depends  upon  the  rapidity  with  which  the  vari- 
ous changes  of  temperature  are  made,  and  the  ex- 
tremes of  temperature  that  are  used.  That  butter  will 
have  the  best  texture  which  has  seen  the  fewest  pos- 
sible changes  of  temperature  between  the  time  the  milk 
is  di*awn  from  the  cow  and  the  time  it  is  churned, 
and  in  which  also  all  the  necessary  changes  of  tem- 
perature have  been  made  most  gradually.  Not  only 
will  such  butter  have  the  best  texture  at  low  tem- 
peratures, but  it  will  stand  the  effec'ts  of  high  tem- 
peratures better.  In  other  words,  it  "  stands  up " 
under  the  heat  better  than  butter  that  during  the  pro- 
cess of  manufacture  has  been  subject  to  sudden  and 
great  changes  of  temperature,  although  the  final  result 
may  have  been  to  keep  it  at  a  low  temperature. 
The  effects  of  ripening  are  more  important  and  more 
marked  upon  the  flavor  of  the  butter  than  upon  the 
texture.  It  is  during  the  ripening  that  the  charac- 
teristic flavors  of  the  butter  are  largely  brought  out. 
It  is  not  necessary  to  the  manufacture  of  the  butter 
itself  that  the  cream  be  ripened  at  all.  Butter  may 
be  made  from  cream  just  as  soon  as  it  is  separated 
from  the  milk,  but  it  will  be  of  a  distinctly  different 
quality  from  that  made  from  ripened  cream.  By 
ripening  in  the  ordinary  sense  is  meant  the  produc- 
tion   of  lactic    acid    in  the  cream. 

In    some    attempts    to    substitute    other    acids    for 


Origin    of  Btttter   Flavors,  129 

lactic  acid  in  ripening-,  Tiemann''^'  fonnd  that  in  cream 
to  which  a  small  amount  of  hydrochloric  acid  had 
been  added  there  was  no  difficulty  in  churning  the 
butter,  that  the  general  flavor  of  the  butter  was 
good,  but  that  it  lacked  in  aroma  and  had  a  some- 
what  oily   texture. 

There  is  some  doubt  as  to  the  origin  of  the 
characteristic  flavors  which  are  developed  in  the  cream 
during  the  ripening  process.  These  flavors  are  un- 
doubtedly due  to  the  presence  of  certain  volatile  sub- 
stances— fats,  bacterial  products,  or  ether- like  com- 
pounds— which  are  formed  during  the  ripening  pro- 
cess. It  was  formerly  supposed  that  the  production 
of  the  characteristic  flavors  was  almost  wholly  a  pro- 
cess of  oxidation,  and  that  cream,  in  order  to  be  prop- 
erly ripened,  and  to  develop  the  best  flavors,  must  be 
supplied  with  an  abundance  of  oxygen  in  pure  air 
during  the  process.  Our  knowledge  of  the  presence  of 
germs  in  milk  and  cream  and  the  effect  of  their 
growth  upon  the  various  constituents  of  the  milk,  has 
led  us  to  modify  these  views.  At  the  present  time  it 
seems  probable  that  the  growth  of  germs  which  pro- 
duce lactic  acid  has  much  to  do  with  the  production 
of  the  characteristic  flavors  of  ripened  cream.  It  has 
been  asserted  by  some,  notably  Conn,  that  the  produc- 
tion of  the  flavors  is  due  to  the  growth  of  specific 
flavor -producing  germs  that  are  largely  independent  of 
the  formation  of  lactic  acid,  but  this  view  does  not 
seem  to  explain  all  of  the  phenomena  of  the  appear- 

*Milch  Zeitung,  xxiii  p.  701. 
I 


130  3fnk   and   Its    Products. 

ance  of  such  flavors,  and  it  is  by  no  means  certain 
that  the  flavors  are  not  in  part  produced  as  the  result 
of  direct  oxidation.  It  is  found  in  practice  that  the 
regulation  of  the  production  of  lactic  acid  is  the 
chief  means  in  controlling*  the  flavor. 

The  means  of  2)roduciug  lactic  acid. — In  order  that 
the  milk  or  cream  should  ripen,  or  become  sour,  it 
is  necessary  that  germs  of  lactic  acid  fermentations 
should  gain  access  to  it,  and  that  a  temperature  favor- 
able to  their  normal  development  should  be  secured. 
The  presence  of  the  germs  may  be  left  to  chance 
inoculation,  or  they  jnay  be  artificially  supplied. 
Under  ordinary-  conditions,  by  the  time  the  cream  has 
been  separated  from  the  milk,  there  will  have  reached 
it  a  sufficient  number  of  germs  of  fermentation  to 
cause  a  rapid  production  of  lactic  acid,  though  the 
number  will  vary  from  day  to  day  and  from  time  to 
time,  and  a  certain  amount  of  acid  cannot  be  de- 
pended upon  within  any  given  specified  time.  The 
inoculation  is  more  certain,  and  the  desired  degree 
of  acidity  will  be  more  surely  reached,  at  the  end 
of  a  given  time,  if  the  germs  are  added  in  suffi- 
cient quantity  artificially.  The  source  of  the  inocu- 
lation may  be  buttermilk  or  cream  from  preceding 
churnings,  or  it  may  be  in  the  form  of  an  artificially 
prepared  "starter"  of  sour  skimmed  milk,  or  it  may 
be  in  the  form  of  am*  of  the  so-called  commercial 
lactic  ferments.  It  is  desirable  that  none  but  the 
proper  germs  should  find  access  to  the  milk,  and 
in  relying  upon  natural  means  there  is  always  more 
or  less  danger  that   putrefactive  and  other  undesirable 


Commercial   Lactic   Ferments.  131 

ferments  may  gain  access  to  the  cream.  As  between 
the  various  forms  of  artificial  starter,  there  is  not 
much  to  be  said.  It  is  generally  held  that  a  starter 
made  from  skimmed  milk  is  less  likely  to  contain 
germs  other  than  those  desired  than  when  cream, 
whole  milk,   or  even  buttermilk  are  used. 

With  regard  to  the  use  of  the  various  commer- 
cial bacterial  ferments,  there  is  considerable  diversity 
of  opinion.  Their  use  was  first  recommended  several 
years  ago  in  Denmark,  as  a  result  of  the  researches 
of  S torch,  and  has  grown  rapidly,  both  in  Denmark 
and  Germany,  until  at  the  present  time  a  large  part 
of  the  butter  produced  in  the  former  country  is  made 
from  cream  first  pasteurized,  and  then  ripened  with 
the  aid  of  an  artificial  bacteria  culture.  The  use 
of  such  ferments  has  only  slightly  extended  to  this 
country,  chiefly  through  the  medium  of  Hansen's 
lactic  ferment. 

In  this  country  Conn  has  been  the  chief  investi- 
gator of  similar  organisms.  From  1890  to  1893*  he 
isolated  several  organisms,  the  culture  of  which  in 
cream  improved  the  flavor  of  the  resulting  butter 
to  a  greater  or  less  extent.  In  the  latter  year  he 
discovered  in  a  can  of  milk  sent  from  Uruguay  to 
the  World's  Columbian  Exposition  at  Chicago,  a 
germ  so  much  better  in  this  respect  that  it  alone 
has  since  been  used,  and  cultures  of  it  placed  upon 
the  market  under  the  name  of  B.41  (Bacillus  No. 41). 

A  series  of  investigations  by  Farrington  and  Rus- 

*Storrs  Agricultural  Experiment  Station,  Reports  1890-93. 


13: 


Milk    and   Its    Products. 


sell,*  in  Tvhich  a  large  number  of  samples  of  butter 
were  made  from  cream  ripened  by  the  use  of  B.  41, 
and  in  the  ordinary  way,  or  "  normally,"  and  sub- 
mitted to  the  judgment  of  several  experts  who  were 
ignorant  of  the  process  of  manufacture,  led  to  the 
conclusion  that  the  "Conn  culture,  B.  -11,  did  not 
improve  the  flavor  of  the  separator  butter  ripened 
for  one  day  at  a  high  temperature,  or  of  that  ripened 
for  a  longer  time  at  a  lower  temperature ;  on  the 
contrary,  the  score  of  the  fresh  B.  41  butter  by 
the  different  judges  was,  in  the  majority  of  cases, 
materially  lower  than  that  of  normal  butter.  ^  H<  ^ 
With  separator  butter  in  cold  storage,  that  made  with 
B.  41  deteriorated  less  than  did  the  normal  butter. 
When  taken  from  storage  there  was  but  little  differ- 
ence in  flavor  between  these  two  butters,  although 
the    normal    butter    when    fresh    scored   higher." 

The  difference  in  the  flavor  of  the  two  kinds  of 
butter  when  fresh,  as  indicated  by  the  different 
judges,    is    shown    in   the    table: 


Gurler. 

Barber. 

Moore. 

General 
average 
scores. 

Number   of    butter    packages 
scored    

Average  score  of  normal  but- 
ter   

Average  score  of  B.  41  butter. 

14 

44.4 
43.7 

14 

45.3 
44 

12 

45.1 
43 

45.3 
43.9 

Difference  in  favor  of  normal 
butter 

.7 

1.3 

2.1 

1.4 

*Wisconsin  Agricultural  Experiment  Station,  Bulletin 


Temperature   of  Ripening.  133 

On  the  other  hand,  a  considerable  number  of  fac- 
tories in  this  country  have  secured  an  increased  flavor 
and  quality  in  their  product  from  ripening  their 
cream  with  the  aid  of  either  Hansen's  ferment  or  B.  41. 

The  present  status  of  the  whole  matter  seems 
to  be  that  the  various  commercial  artificial  ferments 
are  now  prepared  in  such  form  that  they  are  readily 
transported,  they  retain  their  vitality  for  a  consider- 
able length  of  time,  and  are  practically  free  from 
any  undesirable  germs.  Their  use  in  careful  hands 
is  likely  to  be  followed  with  uniformly  good  results. 
Still,  where  all  of  the  surroundings  are  cleanly  and 
the  atmosphere  pure,  the  use  of  such  artificial  germs  is 
not  necessary  to  produce  butter  of  the  highest  quality. 

Temperature  of  ripening.  —  The  various  germs  of 
lactic  fermentations  find  their  optimum  growth  point 
at  from  80"  to  90°  F . ,  and  milk  or  cream  kept  at  those 
temperatures  will  most  rapidly  become  sour.  The 
effect  of  such  high  temperatures,  while  favorable  to 
the  production  of  lactic  acid,  is  less  favorable  to 
the  texture  of  the  butter,  and  on  this  account  it  is 
desirable  to  ripen  the  cream  at  as  low  a  tempera- 
ture as  will  insure  a  fairly  rapid  growth  of  the  lactic 
germs.  A  temperature  of  from  60°  to  70°  F.  will 
ordinarily  bring  this  about.  The  amount  of  acid  de- 
veloped in  any  given  length  of  time  will  depend  not 
only  upon  the  temperature  at  which  the  cream  has 
been  kept,  but  also  upon  the  number  and  activity  of 
the  germs  originally  present,  so  that  if  we  have  a 
thorough  inoculation  to  start  with,  a  lower  temper- 
ature will   be  sufficient    to  cause    the    development  of 


134  Milk   and   Its   Products. 

the  requisite  amount  of  acid ;  but  if  only  a  slight 
inoculation  is  present,  a  higher  temperature  will  be 
necessary.  Ordinarily,  there  will  be  more  germs 
present  in  the  atmosphere  during  the  warm  months 
than  in  the  winter,  consequently  a  lower  temperature 
will  bring  al)out  the  same  degree  of  acidit}'  in  a 
shorter  time  in  summer  than  in  winter. 

The  amount  of  acid  necessary. — The  amount  of 
acid  that  it  is  desirable  to  have  in  the  cream  at 
the  time  of  churning  depends,  of  course,  largely  upon 
the  flavors  desired  by  the  consumer.  It  is  important 
that  whatever  amount  is  desired  should  be  uniform 
from  day  to  day.  By  far  the  larger  proportion  of 
consumers  prefer  the  flavors  that  are  characteristic  of 
ripening  till  sufficient  acid  to  slightly  coagulate  the 
casein  is  present.  Consumers  of  delicate  taste 
readilj'  distinguish  between  the  flavors  due  to  a 
greater  or  less  amount  of  acid,  and  it  is  highly  de- 
sirable that  some  means  of  determining  the  amount 
of  acid  present  be  available.  The  butter -maker  of 
trained  senses  has  little  difficulty  in  distinguishing  by 
the  somewhat  thickened  and  glistening  appearance  of 
his  cream,  when  stirred,  the  proper  condition  of  the 
cream  for  churning.  Besides  this,  there  are,  fortunately, 
more  exact  means  for  determining  the  acidity. 

Acid  tests. — Dr.  A.  G.  Manns  first  suggested  the 
use  of  an  alkali  of  known  strength  to  determine  the 
proper  acidity  of  cream  for  churning,  and  devised 
what  is  known  as  Manns'  acid  test.  It  simply  con- 
sisted in  neutralizing  the  acid  in  the  cream  with  a 
standard  alkali,   the  standard   used  being  that  known 


Determination   of  Lactic   Acid.  135 

to  chemists  as  decinormal,  or  -^o~,  and  the  acidity  was 
reckoned  in  terms  of  cubic  centimeters  of  alkali  re- 
quired to  neutralize  the  acid  in  a  given  quantity  of 
cream.  In  the  use  of  this  test,  an  indicator  which 
changes  color  according  as  the  medium  is  acid  or 
alkaline,  is  used.  A  convenient  indicator  is  phenol- 
phthalein,  which  is  colorless  in  acid  solutions  and 
pinkish  in  alkaline.  Later,  Professor  Farrington* 
devised  tablets  containing  a  known  amount  of  alkali 
for  the  same  purpose,  known  as  Farrington's  alkaline 
tablets.  Each  tablet  contains  an  amount  of  alkali 
equal  to  3.8  cubic  centimeters  of  decinormal  alkali, 
and  a  sufficient  amount  of  phenolphthalein  indicator. 
The  cream  to  be  tested  is  measured,  and  to  it  is 
added  a  solution  of  the  tablets  (one  tablet  in  ten 
cubic  centimeters  of  water)  until  the  cream  retains  a 
pinkish  tinge.  The  tablet  solution  should  always 
be  fresh,  not  more  than  ten  hours  old.  The  tab- 
lets themselves  will  keep  indefinitely.  The  proper 
degree  of  acidity  is  indie tated  when  30-35  c.  c.  of 
Farrington  tablet  solution,  or  11-13  c.  c.  of  deci- 
normal alkali,  are  required  to  neutralize  the  acid  in 
20  cubic  centimeters    of   cream. 

Determ f nation  of  lactic  acid  in  milk  or  cream. — Far- 
rington's alkaline  tablets  may  also  be  conveniently 
used  to  determine  the  percentage  of  lactic  acid  in  any 
given  sample  of  milk  or  cream.  In  order  to  do  this, 
it  is  onl}^  necessary  to  understand  that  equal  volumes 
of   normal   or   decinormal   acids    and   alkalies    neutral- 

*Bull.  32,  111.  Agr.  Exp.  Sta.      Bull.  52,  Wis.  Agr.  Exp.  Sta. 


136  Milk   and   Its   Products. 

ize  each  other ;  and,  further,  that  a  normal  solu- 
tion of  lactic  acid  contains  90  grams  of  acid  in 
each  liter,  or  1,000  c.  c.  A  decinormal  solu- 
tion would  contain  1-lOth  as  much,  or  9  grams 
in  each  liter,  and  a  cubic  centimeter  would  con- 
tain ^;oooth  as  much  as  a  liter,  or  .009  grams 
of  lactic  acid.  Each  tablet  of  the  Farrington 
alkali  is  equal  in  strength  to  3.8  c.  c.  of  de- 
cinormal alkali,  and  if  the  tablet  solution  is 
made  by  dissolving  10  tablets  in  100  c.  c.  of 
water,  each  cubic  centimeter  of  the  solution  will 
be  equal  to  .38  c.  c.  of  decinormal  alkali,  and 
will,  therefore,  neutralize  .38  of  .009  grams,  or 
.0034  grams,  of  lactic  acid. 
^M|l  To   determine    the  percentage  of  acid   in    anj- 

given  sample  of  milk  or  cream,  any  convenient 
amount,  as  20  c.  c,  of  the  sample  to  be  tested 
is  measured  out,  and  the  tablet  solution  is  ad- 
ded from  a  burette  or  graduated  cylin- 
der till  the  milk  retains  a  pinkish  tinge. 
If  this  occurs  when  1  c.  c.  of  the  tablet 
solution  has  been  added,  the  20  c.  c. 
Bu-'  of  milk  contain  .0034  grams  of  lactic 
acid;  but  20  c.  c.  of  milk  weigh  20.64 
grams  (sp.  gr.  milk,  1.032),  therefore  the  per- 
centage of  lactic  acid  is  .0034^-20. 64=. 00017, 
or  .017  per  cent.  If  more  than  1  c.  c.  of  f^i^J 
the  tablet  solution  is  required  to  neutralize 
the    acid,  or   if   more    or    less    than   20    c.    c.  ^ 


/ 


O-i-ID 

n-ffso 


30-S.70 


of   milk   or   cream    are   taken,    the    percentage    Graiiua- 
of    acid    will    be    found    by    multiplying    the    cylinder! 


Further   Effects   of  Ripening.  137 

number  of  cubic  centimeters  of  tablet  solution  re- 
quired by  .0034  and  dividing  by  the  number  of 
grams   of    milk  taken  (grams  of  milk  =  c.  c.  X  1.032). 

Further  effects  of  ripening. — Besides  affecting  the 
flavor,  it  is  believed  that  ripening  aids  in  the  ease  of 
churning,  in  the  completeness  of  churning,  and  in 
improving  the  keeping  quality  of  the  resulting  butter. 
It  was  formerly  supposed  that  sweet  cream  could  not 
be  churned  into  butter,  and  in  fact  with  but  a  moder- 
ate percentage  of  fat  (15  to  20  per  cent)  it  does 
churn  with  much  more  difficulty  than  the  same  cream 
after  it  has  been  ripened  ;  but  since  the  introduction 
of  the  separator,  and  the  consequent  production  of 
a  much  heavier  cream,  it  has  been  found  that  sweet 
cream  can  be  churned  into  butter  quite  as  readily 
as  ripened  cream.  In  cream  containing  but  a 
moderate  amount  of  fat,  it  is  necessary  to  reduce  the 
temperature  from  six  to  eight  degrees,  in  order  to 
churn  it  sweet.  The  difference  in^  the  keeping 
quality  of  ripened  and  sweet  cream  butter  is  like- 
wise not  so  great  as  it  was  formerly  supposed  to  be. 
In  fact,  sweet  cream  butter,  if  properly  made  and 
kept,  will  in  a  short  time  very  closely  approach  the 
qualities  of   ripened  cream  butter. 

Effects  of  churning  cream  of  different  degrees  of 
ripeness. — If  parcels  of  cream  of  different  degrees 
of  ripeness  are  mixed  together  and  then  churned,  it 
will  be  found  that  the  different  creams  will  churn 
differently.  One  will  produce  butter  in  a  shorter 
time  than  another,  or  with  less  agitation.  The  con- 
sequence  is    that    when    this     occurs    the     churn     is 


138  Milk   and   Its    Products. 

stopped  before  the  churning  is  completed,  and  much 
fat  is  lost  in  the  buttermilk.  It  is  a  matter  of 
considerable  practical  importance,  so  far  as  loss  of 
fat  is  concerned,  and  to  some  extent  also  upon  the 
flavor  of  the  butter,  that  all  of  the  cream  churned 
at  one  time  should  be  ripened  together,  evenly  and 
uniformly.  If  creams  of  different  ages  are  to  be 
churned  together  they  should  be  mixed  together  at 
least  twelve  hours  before  churning,  so  that  the  con- 
dition of  acidity  shall  be  the  same  throughout  the 
whole   mass. 

Bad  effects  of  over -ripening. — When  too  much  lactic 
acid  is  developed  in  the  cream  the  casein  is  firmly 
coagulated,  and  in  the  process  of  churning  is  broken 
up  into  minute  granules,  which  become  incorpo- 
rated into  the  butter  in  the  form  of  white  specks  or 
flakes  of  casein.  Such  white  specks,  besides  injur- 
ing the  appearance  of  the  butter,  greatly  detract 
from  its  keeping  qualities,  as  the  putrefactive  fer- 
mentations soon  set  up  in  them  and  give  rise  to 
disagreeable  flavors.  Danger  from  this  source  is 
liable  to  be  present  if  the  coagulation  of  the  cream 
has  gone  so  far  that  any  whey  has  separated.  The 
cream  should  in  all  cases  be  churned  before  the  ripen- 
ing process  has  reached  this  point.  It  was  formerly 
supposed,  and  is  still  generally  believed,  that  the  pro- 
duction of  an  excess  of  lactic  acid  in  ripening  tends 
to  a  loss  of  butter,  from  the  fact  that  the  acid 
dissolved  or  "cut"  the  fat,  causing  it  to  disappear. 
This  has  been  shown,  both  theoretically  and  practi- 
cally, not  to  be  the  case.      Lactic  acid  has  no  appre- 


Effects  of  Over -Ripening.  139 

ciable  effect  upon  fat,  so  far  as  dissolving*  or  decom- 
posing it  is  concerned,  and  cream  may  be  held  until 
the  whey  has  separated  to  the  full  extent  without 
any  loss  in  the  amount  of  butter  that  it  is  possible 
to  churn  from  it.  The  chief  evil  effect  in  over- 
ripening  is  in  the  production  of  strong  and  undesir- 
able flavors  accompanying  the  undue  production  of 
lactic  acid. 


CHAPTER  VIII. 

CHUBXIXG. 

The  process  of  causing  the  particles  of  butter  fat 
to  unite  into  masses,  so  that  they  may  readily  be 
separated  from  the  milk  serum,  is  called  churning. 
Such  union  of  the  particles  of  fat  is  ordinarily 
brought  about  by  agitation  of  the  cream  in  a  suit- 
able vessel,  called  a  churn.  If  milk  or  cream  be 
agitated  at  a  temperature  somewhat  below  the  melt- 
ing point  of  butter  fat,  the  particles  of  fat,  as  they 
pass  by  one  another,  agglutinate  themselves  into 
masses,  and,  the  process  being  continued,  the  fii-st 
formed  masses  continue  uniting,  until  finally  the 
whole  body  of  fat  may  be  brought  together  in  a  prac- 
tically solid  mass.  The  conditions  influencing  the 
separation  of  fat  in  this  way  are,  first,  the  viscosity 
of  the  milk ;  second,  the  ripeness  of  the  cream  ; 
third,  the  temperature;  fourth,  the  nature  of  the 
agitation;   fifth,  the  quality  of  the  globules  of  fat. 

The  viscosity  of  the  7)iiU\ — The  viscosity  of  the 
milk  affects  the  churning,  in  that  it  tends  to  keep 
the  particles  of  fat  from  moving  freely  upon  one 
another,  and  in  that  the  viscous  portions  of  the 
milk,  notably  some  of  the  albuminous  matter,  form  a 
more    or    less    dense    layer    about    the    fat     globules. 

(140) 


Temperature    of   Churning.  141 

tending  to  keep  them  apart.  The  more  viscous  the 
milk,  then,  the  greater  the  difficulty  with  which  it 
will  churn. 

The  ripeness  of  the  cream. — The  ripeness  of  the 
cream  affects  the  churning,  largely  because  of  its 
effect  upon  the  viscosity  of  the  milk.  The  produc- 
tion of  lactic  acid  in  milk  always  has  the  tendency 
to  render  it  less  viscous,  and  sour  milk  or  cream, 
therefore,  will  churn  more  readily  than  sweet  for 
this  reason.  The  viscosity  of  the  milk  must  be 
distinguished  from  the  thickness  of  the  milk,  due 
to  the  coagulation  of  the  casein.  Souring  of  the 
milk  renders  it  less  viscous,  but  at  the  same  time 
by  coagulating  the  casein  renders  it  thicker  and 
less   fluid. 

The  temperature. — The  temperature  is  the  most  im- 
portant condition  affecting  churning.  Whether  the 
particles  of  fat  shall  unite  as  they  pass  by  one 
another  when  the  liquid  is  in  motion,  dej^ends  very 
largely  upon  their  temperature  and  degree  of  plas- 
ticity. If  the  temperature  is  too  low,  the  globules 
of  fat  are  so  hard  that  when  they  hit  one  another 
they  do  not  stick  together.  If,  on  the  other  hand, 
the  temperature  is  too  high,  the  effect  of  agita- 
ting the  globules  of  fat  is,  instead  of  causing  them 
to  unite,  to  break  them  up  into  still  smaller  glob- 
ules, and  so  render  the  emulsion  more  permanent. 
The  range  of  temperature  through  which  the  parti- 
cles of  fat  may  be  made  to  unite  is  considerable. 
The  extreme  limits  may  be  placed  at  from  46°  to 
80°    F.      But    while    butter    may    be    churned    from 


142  Milk  and  Its  Products. 

milk  or  cream  through  this  wide  range  of  tempera- 
ture, the  quality  of  the  butter  is  very  seriously  af- 
fected. The  butter  is  in  the  best  condition  when  it 
is  churned  at  such  a  temperature  that  the  particles 
of  fat  unite  readily,  and  when  united  form  fii-m 
masses  or  granules  of  butter.  The  temperature  at 
which  this  desiral)le  end  is  brought  about  varies 
under  a  w4de  range  of  conditions,  the  most  impor- 
tant of  which  are  the  following:  The  individuality  of 
the  animal  ;  the  period  of  lactation  ;  the  nature  of 
the  food  of  the  cows  ;  the  season  of  the  year. 
These  conditions  are  all  conditions  which  affect  the 
melting  point  of  the  butter  fat.  The  higher  the 
melting  point  of  the  fat,  the  higher  the  tempera- 
ture at  which  the  milk  should  be  churned,  and  the 
lower  the  melting  point  of  the  fat,  the  lower  the 
churning  temperature.  Any  condition  which  tends 
to  make  the  butter  fat  hard  will  necessarily  be  fol- 
lowed by  a  rise  in  the  churning  temperature,  and 
any  condition  which  tends  to  make  the  butter  fat 
soft  will  for  the  same  reason  be  followed  by  a 
fall  in  the  churning  temperature.  It  is  impossible, 
then,  to  name  any  single  temperature  which  is  the 
best  or  even  the  proper  one  at  which  to  churn ; 
but  while  there  is  a  considerable  range  of  tempera- 
ture, which  under  different  conditions  may  give  the 
best  results,  still  this  range  is  not  so  wide  as  the 
range  of  temperature  at  which  it  is  possible  to 
churn,  and  the  limits  may  perhaps  be  placed  at  from 
50°  to  66°  F.  In  general,  the  lowest  temperature 
compatible    with     securing     butter     in    a    reasonable 


The    Nature   of  the   Agitation.  143 

length  of  time  will  give  butter  of  the  best  quality. 
The  lower  the  temperature  at  which  the  butter  is 
churned,  other  things  being  equal,  the  more  com- 
pletely will  the  butter  be  removed  from  the  butter- 
milk, the  longer  will  be  the  time  required  for  churn- 
ing, and  the  less  casein  will  be  found  in  the  butter. 
The  nature  of  the  agitation.  —  It  is  generally  be- 
lieved that  the  best  results  follow  from  agitating 
the  cream  in  such  a  way  that  the  particles  of  fat 
are  subject  to  more  or  less  concussion,  though  it 
is  not  at  all  necessarj^  that  this  concussion  should 
take  place.  Mere  gentle  stirring  of  the  cream,  if 
continued  long  enough,  will  bring  butter,  and  agi- 
tating the  cream  by  passing  bubbles  of  air  through 
it  will  also  cause  it  to  churn.  Many  churns  have 
been  devised  which  bring  about  the  churning  by 
agitating  the  cream  with  floats  or  paddles,  and  in 
the  old-fashioned  dash  churn  there  was  a  minimum 
amount  of  concussion,  the  motion  being  largely  that 
of  stirring.  Where  the  agitation  is  brought  about 
by  the  use  of  paddles  or  stirring  instruments,  the 
texture  of  the  butter  is  usually  injured,  because  of 
the  effect  of  the  stirring  motion  upon  the  grain  of 
the  first  particles  of  butter  formed.  The  best  churns, 
then,  are  entirely  hollow  vessels,  barrel  or  box, 
which  bring  about  agitation  of  the  cream  through 
concussion  of  the  particles  upon  the  sides  of  the 
rotating  churn.  The  churning  depends,  also,  upon 
the  rate  of  agitation;  the  faster  the  motion  to 
which  the  particles  of  cream  are  subjected,  the 
quicker   will   be   the   churning.       In   this   respect    the 


144 


Milk    and   Its   Products. 


motion  of  the  particles  and  the  motion  of  the  churn 
must  not  be  confounded.  If  the  motion  of  the  churn 
is  increased  so  that  sufficient  centrifugal  force  is  gen- 
erated  to   cause   the   particles   of  cream   to  partake  of 


Fig.  IG.     Barrel  power  churn. 


the  motion  of  the  churn,  then,  though  the  particles 
may  pass  through  space  at  a  greater  rate  of  speed, 
the  motion  of  the  particles  upon  each  other  will  be 
lessened.  A  maximum  motion  of  the  particles  upon 
each  other  is  obtained  when  the  sj^eed  of  the  churn 
stops    just    short    of    setting    up    centrifugal    force    in 


Size  and  Character  of  Fat  Globules. 


145 


the  clinrn.  This  will  be  found  to  correspond  to  a 
motion  of  the  particles  of  cream  of  about  700  feet  per 
minute. 

The  quality   of  the   glohules   of  fat. — The   quality   of 
the    globules  of  fat,   both  as  to    their  size    and   char- 


Fig.  17.      Sqixai-e  box  power  cliiirii. 

acter,  bears  an  important  part  in  the  phenomena 
of  churning.  So  far  as  the  hardness  or  softness  of 
the  fats  are  concerned,  this  has  already  been  treated 
of  under  the  effect  of  temperature;  but  temperature 
is  not  the  only  influence  which  causes  variation  in 
J 


U6 


Milk    and    Its    Products. 


Fig.  18.    "Simplex"  combined 
churn  and  butter  worker. 


mass    of    liquid    two 


the    hardness    or   softness    of    the    fat.      The   relative 
proportions    of    hard    and    soft    fats    vary    consider 

ably.  When  the  soft  fats 
predominate,  the  churning  is 
easier  than  when  they  are  in 
less  proportion,  while  an  un- 
due proportion  of  hard  fats 
often  renders  churning  ex- 
tremely difficult.  The  size  of 
the  fat  globules  also  bears  an 
important  part  in  the  ease 
and  time  required  for  churn- 
ing. In  passing  through  a 
Large  globules  are  more  likely 
to  hit  each  other  than  are  two  small  ones,  the  rela- 
tive probability  of  their  meeting  and  hitting  being 
in   proportion   to   the    squares    of    their   diameters. 

The  end  of  cJtu ruing. — When  the  particles  of  fat 
have  united  to  such  an  extent  that  they  begin  to  be 
visible  in  the  cream,  the  butter  is  said  to  "break," 
and  from  this  time  on  the  process  of  churning  is  rap- 
idly finished.  Two  things  are  to  be  observed  in  bring- 
ing the  operation  of  churning  to  a  close.  In  the 
first  place,  the  churning  should  be  continued  until 
the  separation  of  fat  is  as  complete  as  possible. 
In  the  second  place,  the  larger  the  masses  of  but- 
ter in  the  churning  the  more  difficult  is  the  re- 
moval of  the  buttermilk.  If  the  cream  is  thor- 
oughly and  uniformly  ripened,  the  separation  will  be 
more  uniform  and  the  churning  more  complete 
than    when    creams    of     different    degrees    of    ripeness 


Conditions  of  Difficult  Churning.  147 

are  churned  together ;  but  under  various  conditions, 
and  from  time  to  time,  the  completeness  of  separation 
varies  with  the  size  of  the  granules  of  butter;  that 
is  to  say,  if  the  granules  have  reached  a  certain  size, 
it  does  not  always  follow  that  the  fat  has  been  re- 
moved from  the  buttermilk  to  the  same  degree,  so 
that  the  size  of  the  granules  of  butter  is  not  a  certain 
indication  of  the  completeness  of  churning.  When  the 
churning  process  is  complete,  the  buttermilk  takes  on 
a  thin,  bluish,  watery  appearance,  quite  distinct  from 
the  thicker  creamy  appearance  of  the  unchurned  cream, 
and  the  churning  should  be  continued  until  this  con- 
dition of  the  buttermilk  is  reached,  even  though  the 
granules  are  increased  in  size  beyond  the  point  favor- 
able to  their  best  separation  from  the  buttermilk. 
The  higher  the  temperature  at  which  the  cream  is 
churned,  the  greater  the  percentage  of  fat  left  in 
the  buttermilk  and  the  more  casein  will  be  incorpo- 
rated wdth  the  butter. 

Difficult  churning. — Conditions  often  arise  under 
which  it  is  very  difficult  or  impossible  to  cause  the 
butter  to  unite  in  granules  and  separate  from  the  but- 
termilk. One  of  the  chief  difficulties  accompanies 
a  small  and  hard  condition  of  the  butter  granules 
with  a  high  viscosity  in  the  cream.  These  con- 
ditions usually  occur  in  the  late  fall  and  early  win- 
ter months,  w^hen  the  cows  are  far  advanced  in  lac- 
tation, and  when  they  are  often  fed  on  dry  food 
of  a  character  to  make  hard  butter  fat.  An  im- 
proper ripening  of  the  cream  often  accompanies 
these    conditions,    so    that   complaints    of   difficulty   in 


148  Mill-   and   Its   Products. 

chiu'iiing  are  usually  numerous  at  this  period  of 
the  year.  These  complaints  readily  yield  to  the 
proper  treatment,  which  is  indicated  under  the  con- 
ditions atfecting  churning,  and  so  far  as  is  known 
there  never  occurs  a  condition  under  which  it  is 
absolutely  impossible  to  churn  the  butter  from  any 
given  sample  of  cream.  The  course  to  be  followed  in 
cases  of  this  nature  is,  first,  to  add  to  the  food  of 
the  cows  something  of  a  succulent  nature,  that  Avill 
cause  the  secretion  of  milk  to  be  greater  in  amount 
and  not  so  viscous.  Second,  to  further  lessen  the 
viscosity  by  bringing  about  a  vigorous  lactic  acid 
fermentation  in  the  milk,  and  in  extreme  instances, 
perhaps,  diluting  the  cream  with  warm  water  or 
weak  brine.  Care  must  be  taken  that  this  dilution 
does  not  go  too  far,  or  difficulty  in  churning  from 
the  thinness  of  the  cream  will  result.  The  produc- 
tion of  lactic  acid  in  good  amounts  and  within  a 
reasonable  time  seems  to  be  an  important  means  of 
overcoming  these  cases  of  difficult  churning.  It  is 
not  unlikely  that  some  of  the  lower  fermentations, 
which  take  place  at  temperatures  below  which  the 
lactic  acid  germs  are  active,  may  in  themselves  have 
a  retarding  effect  upon  the  churning.  These  cases 
of  difficult  churning  are  frequently  accomi^anied  by 
the  production  of  an  acrid  or  bitter  putrefactive 
fermentation    product    in    the    cream. 

If  the  attempt  is  made  to  churn  at  an  extremely 
low  temperature,  the  agitation  of  the  cream  serves 
to  incorporate  with  it  bubbles  of  aii*,  and  the 
cream     froths     or    swells.      When    this    takes   place, 


Helping   Butter    to    ''Break.^'  149 

little  can  be  done  except  to  allow  the  cream  to 
stand  for  several  hours  and  then  warm  it  up 
gradually  four  or  five  degrees  before  again  starting 
the  churn.  There  is  very  much  less  danger  of  swel- 
ling in    the    revolving   churns    than  in  dash  churns. 

Frequently  also,  in  cases  when  the  attempt  is 
made  to  churn  at  the  extreme  lowest  point  possible, 
the  formation  of  butter  stops  just  short  of  the 
breaking  point,  and  further  agitation  does  not  result 
in  an  increase  of  butter.  This  may  be  overcome  by 
slightly  raising  the  temperature,  or  bj'  the  addition 
of  a  little  water  at  a  temperature  of  85°  or  90°  F.; 
or,  what  is  better,  it  can  usually  be  brought  about 
by  the  addition  of  a  little  dry  salt  to  the  churn. 
The  solution  of  salt  in  the  water  of  the  cream 
seems  to  affect  the  viscosity  in  such  a  way  that 
the  formation  of  butter  granules  is  greatly  facilitated. 

When  ripened  cream  is  churned,  there  is  usually 
an  evolution  of  gas  immediately  after  the  agitation 
commences.  This  is  gas  which  has  been  formed  by 
some  of  the  fermentations  going  on  in  the  cream,  and 
the  gas  is  liberated  within  the  first  five  or  ten  min- 
utes. The  temperature  also  rises  two  or  three  degrees 
during  the  operation,  from  the  effect  of  the  friction 
of   the   particles   upon   one    another. 


CHAPTER    IX. 

FIXISHIXa    AXD    MABKETIXa    BUTTER. 

Whex  the  clmriiiug  process  is  complete,  it  still 
remains  to  separate  the  buttermilk  from  the  granules 
of  butter,  and  to  bring  the  whole  into  a  solid,  uni- 
form mass,  suitable  for  consumption  and  properly 
flavored  with  salt.  These  operations  may  be  per- 
formed in  a  variety  of  ways.  Formerly  it  was  the 
custom  to  continue  the  churning  until  the  butter 
was  in  a  measurably  solid  mass,  when  it  was  re- 
moved from  the  churn  and  the  buttermilk  expelled 
bj'  pressure,  at  the  same  time  that  the  salt  was 
incorporated  with  the  butter.  Now  the  buttermilk 
is  uniformly  removed  from  the  butter  by  washing 
with  water  in  the  churn,  and  in  many  instances 
the  salt  is  incorporated  with  it  during  the  whole 
or  part  of  this  operation  ;  but  the  more  common 
practice  is  to  wash  the  butter  in  the  churn  and  to 
work  out  the  surplus  moisture  and  incorporate  the 
salt  upon  a  separate  instrument,  called  a  butter 
w  )rker. 

Washing  the  huffer. — The  churning  should  be 
stopped  as  soon  as  the  buttermilk  is  clear  and  wa- 
tery. If  the  churning  has  been  done  at  the  right 
temperature  and  the  cream  properly  ripened,  this  con- 

(150) 


Washing   Butter.  151 

ditiou  will  occur  wlieii  the  butter  granules  are  not 
larger  than  kernels  of  wheat.  As  soon  as  the  churn 
is  stopped,  the  addition  of  a  little  cold  water  to  the 
contents  of  the  churn  will  facilitate  the  rising  of 
the  smaller  globules  of  butter  through  the  butter- 
milk. The  l)uttermilk  should  then  be  drawn  off 
from  the  Iwttom  of  the  churn,  and  the  butter  al- 
lowed to  drain  thoroughly.  After  the  butter  is  thor- 
oughly drained,  water  at  a  temperature  of  45°  to 
55°  F.  should  be  added  in  amounts  equal  to  two- 
thirds  the  amount  of  buttermilk  withdrawn.  The 
contents  of  the  churn  should  then  be  gently  agitated, 
so  that  the  water  may  come  in  contact  with  each  par- 
ticle of  butter,  but  not  to  such  an  extent  that  the 
particles  will  compact  themselves  into  larger  masses. 
In  about  ten  or  fifteen  minutes,  this  water  should  be 
withdrawn  and  the  butter  allowed  to  drain  as  before, 
after  which  the  butter  should  be  washed  the  second 
time  in  the  same  manner.  This  second  water  should 
run  away  clear,  or  with  a  very  slight  milkiness. 
If  it  is  at  all  milky,  the  butter  should  be  washed 
again,  and  the  washing  continued  until  the  water  does 
run  away  clear.  It  is  desirable  that  as  little  wash- 
ing be  done  as  possible,  and  if  care  is  taken  in 
stopping  the  churning  at  the  right  moment,  and  in 
draining  and  w^ashing  the  butter,  two  waters  will  be 
sufficient.  The  addition  of  a  small  amount  of  salt 
to  the  first  washing  water  will  facilitate  the  removal 
of  the  buttermilk,  but  will  not  add  any  perceptible 
saltiness  to  the  butter.  The  way  in  which  the  wash- 
ing  is    done    perceptibly   affects    the    quality    of    the 


152  Mill'    (Did   Its    Products 

finished  butter,  partieularly  so  far  as  regards  its  tex- 
ture and  percentage  of  water.  The  smaller  the 
granules  of  butter  when  the  churn  is  stopped,  and 
the  colder  the  water  used,  the  more  water  will  re- 
main in  the  butter  without  appearing  in  the  form 
of  drops.  If  the  churning  has  progressed  until  the 
butter  has  formed  masses  the  size  of  a  hickory  nut 
or  larger,  particularly  if  the  butter  is  soft,  it  will 
be  impossible  to  completely  wash  the  buttermilk  from 
the  butter,  and  the  buttermilk  must  necessarih'  be 
removed  in  working.  Such  butter  will  always  re- 
tain in  its  flavor  traces  of  the  buttermilk  so  incor- 
porated  with    it . 

The  texture  of  the  butter  is  also  affected  bj-  the 
temperature  of  the  wash  water.  If  the  butter  comes 
soft,  the  attempt  is  usually  made  to  cool  it  down 
rapidly  by  the  addition  of  large  amounts  of  very  cold 
water.  The  butter  can  be  hardened  up  in  this  way, 
but  it  will  show  the  effect  of  sudden  changes  of 
temperature  afterward  much  more  strongly  than  if  it 
were  cooled  down  more  slowly.  Butter  fat  does 
not  conduct  heat  rapidly,  and  to  become  thoroughly 
warm  or  thoroughly  cool  requires  some  little  time. 
If,  then,  butter  has  been  churned  too  warm,  and 
comes  in  a  soft  condition,  the  washing  process  should 
be  much  prolonged.  Use  the  ordinary  amount  of 
water  and  at  the  ordinary  temperature,  but  allow  the 
butter  to  remain  in  it  until  it  has  had  sufficient  time 
to  thoroughly  adjust  itself  to  the  changed  condition. 
It  can  then  be  taken  out  and  worked  without  dan- 
ger of  ([uickly  becoming   soft    again.       There    is    also 


Working   Butter. 


153 


danger  of  removing  some  of  tlie  more  delicate  flavor- 
ing oils  of  the  butter  by  the  use  of  too  large  an 
amount  of  very  cold  water.      These  flavoring   oils  are 


Fig.  19. 


Eureka"  hand  butter- worker. 


slightly  soluble,  and  more  soluble  at  a  low  tempera- 
ture, so  that  the  drenching  with  large  amounts  of 
very  cold  water  has  a  tendencj-  toward  the  produc- 
tion  of   a   flavorless   or   tallowy   butter. 

Worl'ing. — Working  butter  is  an  integral  part  of 
the  process  of  manufacture,  only  in  so  far  as  it  re- 
lates to  the  incorporation  of  the  salt  and  bringing 
the  butter  into  the  compact  form  necessary  for  con- 
sumption, so  that  all  working  beyond  that  which 
is  necessary  to  bring  about  these  two  things  is  super- 


154 


Milk    and    Its    Products 


fluous,  and,  because  of  the  danger  of  injuring  the 
grain  of  the  butter,  is  objectionable.  The  grain 
of  the  butter  is  least  affected  bj'  working  when  this 
is  done  by  pressure  and  at  a  temperature  of  from 
45°    to    ')'j°  F.       The    amount    of    water    that    remains 


Fig.  20.     "Mason"  table  butter-worker, 


in  the  butter  depends,  as  before  stated,  upon  the 
temperature  and  fineness  of  the  granules.  The  finer 
and  colder  the  butter,  the  more  water  will  it  retain. 
Salting.  —  Salt  is  added  to  butter  solely  for  the 
sake  of  the  flavor  which  it  imparts.  While  salt  has 
undoubted  antiseptic  properties,  these  play  very  little 
part  in  the  preservation  of  butter,  and  need  not  be 
taken  into  consideration.  The  amount  of  salt,  then, 
that    should    be    added    to    butter     depends     entirely 


Salting   Butter. 


155 


upon  the  taste  of  the  consumer  for  whom  it  is  in- 
tended, and  may  vary  from  a  mere  trifle  to  as 
mnch  as  2%  onnces  for  each  ponnd  of  butter. 
The  great  majority  of  consumers,  however,  prefer 
an  amount  ranging  between  %  of  an  ounce  and  1 
ounce    to    the     pound.      The    addition    of   a   uniform 


Fig.  21.    "  Centrifugcil  "  or  vertical  butter-worker. 


amount  of  salt  from  day  to  day  is  a  matter  of 
considerable  importance  in  securing  a  uniform  qual- 
ity of  butter,  and  the  amount  of  salt  should,  there- 
fore, be  based  upon  the  least  variable  factor  possi- 
ble. It  will  be  found  that  from  day  to  day  the 
size  of   the  granules  of   butter  when   washed,  and   the 


156  Milk   and   Its    Products. 

amount  of  water  adhering  to  them,  Avill  vary  consid- 
erably, so  that  the  weight  of  washed  and  drained  but- 
ter will  not  bear  any  definite  relation  to  the  amount 
of  finished  butter,  and  if  the  attempt  is  made  to  gauge 
the  salt  by  the  weight  of  drained  butter,  it  will  be 
found  that  the  degree  of  saltness  will  varj'  considera- 
bly, because  when  more  water  is  contained  in  the 
butter  much  more  of  the  salt  will  pass  out  with 
the  brine.  When  a  separator  is  used  in  creaming, 
the  weight  of  cream  will  be  found  to  bear  a  closer 
proportion  to  the  weight  of  finished  butter  than 
either  the  original  weight  of  the  whole  milk  or  the 
weight  of  the  washed  and  drained  butter,  and  the 
more  uniform  salting  will  be  obtained  if  the  salt 
is  added  in  the  ratio  of  a  certain  percentage  of 
the  weight  of  the  cream.  The  salt  should  be  added 
so  that  it  can  be  readily  and  uniformly  incorporated 
with  the  whole  amount  of  butter.  This  is  con- 
veniently done  while  the  water  is  being  expressed 
from  the  butter  in  the  worker,  and  the  working 
should  continue  until  the  salt  has  completely  dis- 
solved, because  the  salt  has  a  deepening  effect  upon 
the  color  of  the  butter,  and  if  some  undissolved 
portions  remain,  these,  afterwards  dissolving  in  the 
water  contained  in  the  butter,  will  make  a  strong 
brine  at  that  particular  point,  and  consequently  a 
deeper  color,  and  mottled  or  streaked  butter  is  the 
result. 

The  salt  should  be  dry,  of  uniform  grain,  and 
should  readily  and  completely  dissolve  to  a  clear 
solution.     Those  brands  of  salt  which  are  made  from 


Packing   Butter.  157 

the  natural  crystal  give  tlie  best  results  so  far   as  re- 
maining dry  and  freedom   from  caking  are   concerned. 
Brine    salting.— \Yith    many    who     prefer   a    butter 
slightly    salted,    it     is    sometimes    convenient    to    add 
the    salt   through   the   medium    of    brine,    rather   than 
to    mix    it    with    the    butter    in   a  dry  condition.     The 
advantages    of   brine    salting   are   that  a  light  amount 
of    salt    may    be     uniformly    incorporated     with     the 
butter.      It    is   not   possible    to    incorporate   with   the 
butter   a  large    amount   of   salt    in   this   way.     Where 
well -drained    butter    is    salted    at    the     rate     of     one 
ounce    to    the    pound,    there   will  remain   in    the   but- 
ter   about    3    per    cent    of    salt.       Where    butter    is 
washed    twice  with    a  saturated    brine,    there   Avill   re- 
main   in   the   butter   w^hen   w^orked   about   2    per   cent 
of   salt.     In    salting   butter   in  this  manner,  it  is  nec- 
essary   that    the    brine    should    be     prepared    before- 
hand.     This    is   best   done   by  dissolving   the  salt   in 
warm   water,    as    much   as   the   water   wdll   hold,    and 
then  cooling  it    to   the   proper   temperature  to    add   to 
the  butter.     The   brine  in  this   instance  may  take  the 
place    of    the    second   wash   w^ater.      After    the    brine 
has   remained    upon   the   butter   five    or   ten   minutes, 
it   should   be  withdrawn   and  additional  salt   added   to 
it,  or   a  second   portion  of   saturated  brine  added  and 
left   upon    the   butter    for   a   similar   length   of    time, 
after   which   the    brine    may    be    wdthdi-aw^n    and    the 
butter   worked   in   the   ordinary  manner. 

Packing  and  marketing.— After  the  butter  has 
been  worked  until  the  salt  is  completely  dissolved 
and   a    sufficient    amount    of    water    removed,    it    is 


158  Milk   and   Its    Products. 

ready  for  packing.  Butter  that  is  to  be  packed 
and  held  for  any  considerable  length  of  time  should 
be  worked  drier  than  when  it  is  intended  for  im- 
mediate consumption.  Fresh  butter  is  most  highly 
esteemed  in  most  markets  when  it  contains  about  all 
the  water  that  it  will  hold,  but  if  such  butter  is 
held  for  any  length  of  time  the  evaporation  of  water 
from  the  surface  will  lead  to  a  deposition  of  salt, 
which  detracts  much  from  its  appearance  and  sala- 
bleness.  An  ideal  package  for  butter  is  one  that  is 
light,  strong  and  tight.  None  of  the  packages 
in  ordinary  use  are  perfect  in  all  of  these  respects. 
Wooden  packages,  though  light  and  strong,  always 
leak  more  or  less  and  let  in  air.  Tin  packages 
are  more  or  less  objectionable  because  of  the  action 
of  the  salt  upon  the  tin,  and  iron,  and  glass,  and 
crockery  packages,  although  tight  and  clean,  are 
heavy  and  subject  to  breakage.  Packages  made  of 
paper  or  wood  pulp  have  been  used  to  some  extent,  as 
have  also  packages  of  these  materials  covered  with 
paraffine,  but  they  do  not  make  a  very  attractive 
package.  All  things  considered,  tight,  smooth,  well- 
made  tubs  of  ash,  spruce  or  oak  make  the  most 
available  package.  All  wooden  packages  possess  the 
characteristic  flavor  of  the  wood,  which  may  be  im- 
parted to  the  butter  to  a  greater  or  less  extent  if 
it  is  allowed  to  remain  in  them  very  long.  In 
order  to  obviate  this,  the  odor  of  the  wood  should  be 
removed  as  much  as  possible  before  the  butter  is 
packed.  The  package  should  be  thoroughly  steamed, 
and    then    filled   with  hot    water   in   which   some   salt 


Composition   of  Butter,  159 

has  been  dissolved,  and  allowed  to  stand  at  least 
twenty -fonr  honrs,  after  which  it  shonld  be  scalded 
a  second  time  and  then  cooled  with  cold  water. 
Bntter  may  also  be  packed  in  prints  or  monlds, 
especially  for  immediate  consumption.  The  demand 
for  butter  in  this  form  is  increasing,  and  for  nearby 
markets  it  is  one  of  the  most  desirable  forms  of 
packing.  In  cool  weather  and  with  proper  precau- 
tions, prints  may  also  be  shipped  considerable  dis- 
tances with  success.  Prints  are  usually  made  in 
pound  and  half-pound  sizes,  intended  to  go  directly 
upon  the  table  in  the  shape  in  which  they  leave 
the  manufacturer.  Various  shapes  and  sizes  of  prints 
have  been  made,  but  since  the  great  increase  in  the 
demand  for  butter  in  this  shape,  a  standard  size  for 
pound  prints  has  been  settled  upon  that  makes  a 
rectangular  print,  4%  x  2%  x  2%  inches.  These 
prints  are  wrapped  in  parchment  paper  and  packed 
in    specially   made   carrying   boxes. 

Comqyosition  and  quality  of  hutter. — The  average 
composition   of   butter   is    about   as   follows: 

Fat 85  per  cent. 

Casein 1  per  cent. 

Salt 3  per  cent. 

Water 11  per  cent. 

The  percentage  of  fat  should  not  fall  below  80  per 
cent  nor  the  water  rise  above  15  per  cent.  The  per- 
centage of  casein  should  not  exceed  4  per  cent.  The 
percentage  of  fat  in  butter  of  good  quality  often  rises 
to  86  or  88  per  cent.  The  quality  of  butter  is 
judged  upon  its  flavor,  texture,  color,  amount  of  salt, 


160  Milk   (Hid   Its    Products. 

and  its  general  style  and  appearance.  Butter  of  good 
flavor  should  have  the  characteristic  flavors  well  pro- 
nounced. It  should  be  free  from  any-  rancidity,  and 
clean  and  pure  so  far  as  any  extraneous  flavor  is  con- 
cerned. The  determination  of  the  flavor  of  any  sam- 
ple of  butter  is  entirely  one  of  individual  judgment. 
To  some  a  high  flavor  is  one  in  which  the  flavoring 
oils  are  developed  almost  to  the  verge  of  rancidity; 
in  others,  high  flavor  means  a  certain  amount  of  the 
flavor  of  sour  milk  or  buttermilk ;  with  still  others, 
that  butter  is  esteemed  of  the  best  flavor  that  is 
cleanest  and  purest.  The  true  bouquet  of  high -class 
butter  is  a  mild,  distinct,  volatile  flavor  or  combina- 
tion of  flavors  extremely  difiicult  to  describe,  and  only 
met  with  in  perfection  under  the   best   conditions. 

The  texture  of  butter  depends  upon  the  state  of 
the  granular  condition  of  the  fats.  When  the  butter 
is  first  formed  in  the  churn  it  makes  its  appearance 
in  the  shape  of  minute  irregular  granules.  In  the  sub- 
sequent process  of  manufacture  these  granules  never 
completely  lose  their  individuality,  and  constitute  the 
so-called  grain  of  the  butter.  The  more  distinctly 
the  individuality  of  the  granules  is  marked  in  the 
mass  of  butter,  the  better  the  texture.  The  texture 
of  the  butter  is  shown  by  an  appearance  like  broken 
cast  iron  when  a  mass  of  butter  is  broken  in  two 
transversely,  and  when  a  metal  is  passed  through  the 
butter,  as  a  knife  or  trier,  if  the  butter  be  of  the 
best  texture,  no  particles  of  fat  adhere  to  it.  The 
texture  of  the  butter  is  deteriorated  if  the  particles 
of   butter   are    churned   in   too    large    masses,    and    if 


Judging   Butter.  161 

in  the  process  of  working  the  individual  particles 
are  made  to  move  upon  one  another  at  too  high  a 
temperature.  The  mere  warming  of  the  butter  to  a 
point  approaching  the  melting  point  destroys  the 
grain  upon  subsequent  cooling,  even  though  the  mass 
of  butter  may  have  been  undisturbed. 

The  color  of  the  butter  should  be  a  clear,  bright, 
golden  yellow,  such  as  is  naturally  yielded  by  the 
cow  when  feeding  upon  fresh  pasture  grasses.  The 
natural  color  of  the  butter  is  affected  very  largely  by 
the  race  of  the  cow,  by  the  character  of  the  food, 
and  by  the  period  of  lactation.  Scarcely  any  breed 
of  cows  will  yield  a  butter  of  ideal  color  upon  dry 
food  late  in  their  period  of  lactation.  On  the  other 
hand,  one  or  two  races  upon  fresh  pasture  will 
yield  a  butter  of  too  high  a  color  to  suit  the  most 
critical  trade.  The  great  mass  of  butter  made  is 
artificiall}'  colored.  For  this  purpose  a  large  va- 
riety of  substances  has  been  used,  but  the  color- 
ing matter  most  commonly  employed  is  a  prep- 
aration of  annatto  (a  coloring  matter  in  the  seed 
pulp  of  Bixa  orellana)  in  some  neutral  oil.  This 
coloring  matter  is  prepared  of  such  strength  that  only 
minute  quantities  are  necessary  to  be  added  to  the 
cream  to  produce  butter  of  tlie  proper  shade.  Ani- 
line colors  are  also  quite  largely  used  in  the  prep- 
aration of  butter  colors.  They  are  cheaper  and  do 
not  so  easily  fade  as  annatto,  and  some  of  them 
are  harmless  ;  but  because  of  the  liability  of  their 
containing  injurious  or  poisonous  substances  their 
use    is   not    to    be    recommended.      Butter  artificially 


162  Milk    and    Its    Products. 

colored  should  be  uuiform,  of  a  bright  golden 
yellow  color,  free  from  any  reddish  tinge.  The 
demand  of  different  markets  varies  considerably  in 
regard   to   the    shade   of   color    desired. 

In  regard  to  salt,  the  quality  of  the  butter  is 
not  necessarily  affected  by  the  amount  of  salt,  that 
being  established  by  the  demand  of  the  trade  for 
which  it  is  intended,  but  the  salt,  in  whatever  de- 
gree added,  should  be  completely  dissolved,  and 
should  be  uniform  throughout  the  whole  mass  of 
butter.  The  finish  of  the  butter,  in  whatever  form 
packed,  should  be  such  that  it  Avill  present  a  neat, 
clean,  attractive  appearance.  The  different  qualities 
of  butter  are  ranked  in  importance  in  accordance 
with  the   following  scales  : 

Flavor 40  to  45. 

Texture 25  to  30. 

Color     10  to  15. 

Salt        10 

Finish       .   , 5 


CHAPTER  X. 

MILK   FOB    CHEESE   MAKING. 

Cheese  is  a  product  manufactured  from  milk,  into 
which  a  large  part  of  the  solids  are  gathered  together 
in  such  form  that  their  nourishing  qualities  are  re- 
tained, at  the  same  time  that  thej^  are  brought  into 
a  condition  capable  of  preservation  and  convenient 
for  transportation.  The  solids  which  are  concerned 
in  the  manufacture  of  cheese  are  the  casein,  the  fats, 
and  a  considerable  portion  of  the  ash.  The  albumin, 
nearly  all  of  the  sugar,  about  one -third  of  the  ash, 
and  a  small  part  of  the  fat,  escape  during  the  course 
of  manufacture.  The  elimination  of  a  large  part  of 
the  water  is  the  chief  step  in  the  process  of  cheese 
making.  In  general  terms,  cheese  consists  of  about 
equal  proportions  of  water,  fat  and  casein,  with  a 
certain  amount  of  salt  and  minute  quantities  of  milk 
sugar  and  ash.  In  milk,  the  casein  exists  in  a  state 
of  minute  suspension  or  semi-solution.  The  essential 
step  in  securing  the  separation  of  the  water  is  in 
rendering  the  casein  insoluble.  Casein,  like  most 
albuminous  organic  substances,  exists  in  two  forms, 
known  respectively  as  the  soluble  and  the  insoluble 
or  coagulated  form,  and  the  change  from  solution  to 
insolubility   is   termed   coagulation.       In    the    case   of 

(163) 


164  Milk  and  Its  Products. 

casein,  coagulation  may  be  brought  about  by  several 
reagents,  but  the  one  universally  employed  in  cheese 
making  is  a  soluble  ferment  found  in  the  stomachs 
of  young  mammalia  and  in  certain  other  animals, 
known  as  rennet.  By  the  addition  of  rennet  to 
milk,  the  casein  takes  on  the  form  of  a  homogene- 
ous gelatinous  solid,  and  in  changing  its  form  en- 
closes in  its  mass  the  globules  of  fat.  In  bringing 
about  the  change  in  the  casein  in  this  way,  the  ren- 
net acts  by  contact ;  that  is,  its  own  constitution  is 
in  no  way  disturbed,  and  a  minute  amount  of  rennet 
is  capable  of  causing  the  coagulation  of  a  large 
amount   of   milk. 

Quality  of  miU'  for  cJieese  mal'nig. — While  it  is 
scarcely  necessary  to  demonstrate  that  milk  is  val- 
uable for  butter  making  in  proportion  to  the  amount 
of  fat  it  contains,  the  proposition  that  its  percent- 
age of  fat  is  also  a  measure  of  the  value  of  nearly 
all  milk  for  cheese  making  has  not  been  so  readih^ 
accepted.  Indeed,  until  within  a  very  short  time,  the 
prevailing  opinion  among  dairymen  and  cheese -makers 
has  been  that  a  milk  poor  in  fat  was  likely  to  be 
rich  in  casein,  and  hence  more  valuable  for  cheese 
making  purposes.  But  both  fat  and  casein  are  con- 
stituents of  cheese,  and  both  are  of  nearh*  equal  im- 
portance ;  hence,  the  richer  a  milk  is  in  fat,  the 
more  cheese  it  will  make,  and  recent  research  has 
shown  that  for  milks  containing  a  normal  amount  of 
fat  the  yield  of  cheese  will  be  nearly  proportional  to 
the  percentage  of  fat  in  the  milk. 


Relation    of  Fat    to    Casein. 


165 


Van  Slyke,*  in  a  series  of  investigations  extend- 
ing over  several  years,  and  including  the  milk  of  not 
less  than  fifteen  hundred  different  cows,  found  that  as 
the  percentage  of  fat  increased  the  percentage  of 
casein  increased  in  a  nearly  constant  ratio  ;  or,  to 
quote  his  own  words  :  "While  we  have  noticed  con- 
siderable variation  when  we  considered  individual 
herds,  we  have  found  that,  as  a  rule,  there  were  two- 
thirds  of  one  pound  of  casein  for  each  pound  of 
fat  in  the  milk,  whether  the  milk  contained  3  or  4 
per  cent  of  fat  ;  though  this  normal  relation  was  con- 
siderably affected  in  the  season  of  1893  by  the  effects 
of  drought  upon  the  pastures.  *  *  >i^  >i<  When 
the  amount  of  fat  in  the  milk  increased  beyond  4% 
per  cent,  there  was  a  gradual  but  slight  diminution 
of  casein  for  each  pound  of  fat." 

The  accompanying  tables  give  the  data  upon  which 
Dr.  Van  Slyke's  opinions  were  based  : 

Table  showing  relation  of  fat  to  casein  in  normal  milJc. 


Average 

Group. 

Percent  of 
fat  in  milk. 

Number  of 
samples. 

Average  per 

cent  of  fat  in 

each  group. 

Average  per 
cent  of  casein 
in  each  group 

pounds  of 

casein    for 

each  pound  of 

fat. 

I. 

3  to  3.5 

22 

3.35 

2.20 

0.66 

II. 

3.5  to  4 

112 

3.72 

2.4« 

0.66 

III. 

4  to  4.5 

78 

4.15 

2.70 

0.65 

IV. 

4.5  to  5 

16 

4.74 

3.05 

0.64 

V. 

5  to  5.25 

7 

5.13 

3.12 

0.61 

*New  York  Agricultural  Experiment  Station,  Bulletin,  No.  68,  New  Series. 


166 


Milk   and   Its    Products. 


Table  showing  relation 

of  fat  in  milk  to  yield  of  cheese. 

Group. 

Per  cent  of  fat  in 
milk. 

Pounds  of  green 

cheese  made  from  100 

lbs.  of   milk. 

Pounds  of  green 
cheese  made  for  one 
pound  of  fat  in   milk. 

I. 
II. 

in. 

IV. 
V. 

3  to  3.5 
3.5  to  4 

4  to  4.5 
4.5  to  5 

5  to  5  25 

9.14 
10.04 
11.34 
12.85 
13.62 

2.73 
2.70 
2.73 
2.71 
2.G6 

Babcock*  tabulated  the  results  of  a  large  num- 
ber of  observations  in  factories  in  Wisconsin  in  the 
accompanying  tables,  and  while  agreeing  in  the  main 
with  Van  Slyke,  was  forced  to  conclude  that,  "  at  the 
same  season  of  the  j'ear,  rich  milks  do  not  yield  as 
much  cheese  in  proportion  to  the  fat  they  contain  as 
do  poor  milks,  but  that  a  rich  milk  toward  the  end  of 
the  season  may  do  as  well  as  a  much  poorer  milk 
earlier  in  the  season." 

Table  showing   yield  of  cheese  in   Wisconsin  factories    according    to 
per  cent  of  fat  in  milk. 


No.  of 
groups. 

No.  of 
reports. 

Range  of  fat 
per  cent. 

Average  per 
cent  of  fat. 

Average 

yield  of 

cheese  per 

100  lbs.  milk. 

Lbs.  of  cured 

cheese  for 

1  lb.  fat. 

1 

24 

under  3.25 

3.126 

9.194 

2.941 

2 

90 

3.25—3.50 

3.382 

9.285 

2.730 

3 

134 

3.50-3.75 

3.600 

9.407 

2.613 

4 

43 

3.75-4.00 

3.839 

9.806 

2.562 

5 

46 

4.00—4.25 

4.090 

10.300 

2.512 

6 

20 

over  4.25 

4.447 

10.707 

2.407 

All  groups.  . 

347 

3.64 

9.566 

2.628 

♦Wisconsin  Agricultural  Experiment  Station,  11th  Annual  Report,  p.  137. 


Belafion    of  Fat    to    Casein.  167 

Table  showing  yield  of  cheese  in  JVisconsi)i  factories  by  months. 


Monti 


April     .    ■ 
May 

June  .  . 
July  .  .  . 
Augnst 
September 
October  . 
November 


"VThole  season   . 


No.  of 
reports. 


347 


Average  per 
cent  of  fat. 


3.480 
3.493 
3.497 
3.554 
3.634 
3.836 
4.076 
4.254 


3.64 


Average 

yield  of 
cheese    per 
100  lbs.  milk. 


9.154 
9.447 
9.367 
9.231 
9.335 
9.955 
10.562 
10.947 


9.566 


Lbs.  of  cured 
cheese  for 
lib.  of  fat. 


2.630 
2.704 
2.679 
2.593 
2.568 
2.594 
2.591 
2.573 


2.628 


Table  showing  yield  of  cheese  for  one  pound  of  fat  for  each  month. 


■ 
Percent  of  fat. 

April  and 
May. 

June 

July. 

August. 

Sept. 

October 

and 

Novemb'r 

No. 

No. 

No. 

No. 

No. 

No. 

Under  3.25  .... 
3.25—3.50     .... 

12-2.96 
33-2.73 

6     "^  90 

3 — '^  89 

3—''  88 

23—2.74 

20—2.70 

11—2.73 

3—2.85 

3.50-3.75     .... 

34-2.62 

32—2.63 

29-2.58 

24—2.54 

10—2.67 

5—2.81 

3.75—4.00     .... 

7—2.53 

3—2.47 

7—2.46 

7—2.53 

13—2.61 

6—2.62 

4.00—4.25     .... 

3—2.56 

2—2.30 

4—2.33 

3—2.35 

9—2.47 

15—2.64 

Over  4.25     .... 

1-2.15 



1—1.95 

1—2.13 

17—2.46 

On    the    other    hand,    Deau^^    has    found   that    uni- 


*  Ontario  Agi'icultui-al  College,  21st  Annual  Report,  p.  44. 


168 


Milk    and    Its    Prodxcfs. 


formly  a  rii^li  milk  yiolds  less  olieose  in  proportion 
to  the  fat  contained  in  it  than  a  poor  milk.  His 
experiments  covered  a  whole  season's  work  in  a 
single  factory,  the  average  results  of  which  are  shown 
in    the    following   table: 

Yield  of  cheese  from  rich  and  poor  milk. 


Num- 
ber of 
experi- 
ments. 

Per  cent  of  fat  in 
milk. 

Pounds  of  green  cheese 
for  one  pound  of  fat 
in  milk. 

Richer 
milk. 

Poorer 
milk. 

Richer 
milk. 

Poorer 
milk. 

April 

c 

G 

15 

15 

12 
12 

14 
14 

13 
13 

12 
12 

13 
13 

4.21 
4.09 
3.94 
3.78 
3.82 
4.01 
3.99 

3.39 
3.30 
3.1G 
3.00 
2.91 
3.06 
3.2C 

2.G6 
2.68 
2.68 
2.73 
2.74 
2.68 
2.82 

'^  86 

May 

•^  84 

o  q^ 

Julv 

August 

3.06 
3  14 

September 

■     

October      ...... 



3.06 

3.05 

Average 

3.98 

3.15 

2.71 

2.99 

The  practical  bearing  of  the  relation  of  the  fat 
to  the  casein  arises  in  the  question  as  to  whether, 
where  milk  is  bought  for  cheese  making,  it  should 
be  paid  for  by  weight  or  according  to  its  percent- 
age of  fat.  It  does  not  require  proof,  that  to  pay 
an  equal  price  per  pound  or  hundred  weight  for 
milk   of   all   qualities   is    a    gross    injustice    to    those 


Relation    of  Fat    to    CanfAn.  169 

who  produce  the  richer  milks.  If  there  were  a 
quick,  accurate  method  of  determining  casein,  the 
logical  practice  would  be  to  pay  for  the  milk  upon 
the  basis  of  its  known  content  of  both  fat  and 
casein;  but  failing  in  that,  it  is  well  to  examine 
in  how  far  we  may  fall  back  upon  the  percentage 
of  fat,  the  determination  of  which  is  both  quick 
and  accurate,  as  a  measure  for  determining  the 
value  of  milk  for  cheese  making.  While  there  is 
some  disagreement,  it  seems  to  be  pretty  well  settled 
that  a  milk  rich  in  fat  is  also  richer  in  casein, 
and  with  milk  of  ordinary  quality,  including  prob- 
ably nine -tenths  of  all  the  milk  produced,  nearh'  in 
proportion  to  the  percentage  of  fat.  So  that,  even 
if  the  richer  milk  does  yield  a  little  less  cheese 
for  each  pound  of  fat,  the  percentage  of  fat  is  a 
much  more  nearly  just  measure  of  its  cheese -pro- 
ducing power  than  is  the  weight  of  the  milk,  the 
measure  now  commonly  employed.  Further,  when 
the  milk  is  so  rich  in  fat  that  the  casein  falls 
considerablj^  below  its  normal  ratio  to  the  fat,  the 
resulting  cheese  will  be  so  much  richer  in  fat 
that  it  will  be  of  considerably  better  quality,  and 
such  milk,  when  pooled  with  milk  poor  in  fat,  will 
so  bring  up  the  quality  of  the  w^hole  product,  that  it 
should  be  paid  for  at  a  correspondingly  higher  rate. 
The  conclusion,  therefore,  is  that  the  percentage  of 
fat  is  by  far  the  most  accurate  measure  at  present 
available  for  the  determination  of  the  cheese -produ- 
cing value  of  milk,  and  that  milk  is  practically  valu- 
able for  cheese  making    in    proportion  to  the  amount 


170 


Milk    and    Its    Products. 


of   fat    that    it   contains,  and   should  l^e    paid   for   ac- 
eording*h\ 

Loss  of  fat  in  cheese  making. — It  has  been  a  gen- 
erall}'  accepted  idea  by  cheese -makers,  that  the  neces- 
sary loss  of  fat  in  the  whey  is  much  greater 
when  the  milk  contains  a  high  percentage  of  fat. 
Indeed,  the  statement  has  been  frequently  made 
that  all  the  fat  in  the  milk  above  4  per  cent  is 
lost  in  the  whey.  This  idea  has  had  much  to  do 
with  the  disinclination  to  value  milk  for  cheese 
making  according  to  its  percentage  of  fat,  and,  in 
fact,  has  been  a  chief  argument  in  favor  of  the 
manufacture    of    skimmed   or   partly   skimmed    cheese. 

The   following    table   by    Van    Slyke*    shows    that 
this    idea    is    erroneous,    and    that    the    loss    of    fat  in 
the   whey   need    be    proportionately   no    greater    when 
the    milk    is    rich    than    when    it    is    poor    in    fat. 
Table  showing    amount  of  fat  lost   and  recovered  in  malcing  cheese. 


Number  of 
experi- 
ment. 

Pounds 
of  fat 
in  100 

11)S. 

of  milk. 

Pounds  of 
fat  lost  in 

100  lbs. 

of  milk. 

Pounds  of  fat 

recovered  in 

100  lbs.  of 

milk. 

Pounds   of  fat 

lost  in  whey 

from  100  lbs. 

of  fat  in 

milk. 

Pounds  of  fat 
recovered  in 
green  cheese 
from  100  lbs. 

of  fat  in  milk. 

1 

2 

3 

4  .    .  •    .   . 

5  •    .... 

6 

7 

8           ... 
9 

2.35 
3.01 
3.88 
3.96 
4.70 
4.73 
4.80 
6.49 
3.70 

0.154 
0.193 
0.277 
0.283 
0.359 
0.331 
0.373 
0.715 
0.269 

2.196 
2.817 
3.603 
3.677 
4.341 
4.399 
4.427 
5.775 
3.431 

6.55 
6.42 
7.15 
7.14 
7.64 
6.99 
7.77 
11.01 
7.26 

93.45 
93.58 
92.85 
92.86 
92.36 
93.01 
92.23 
88.99 
92.74 

Other     investigators     have     abundantly     confirmed 
these   results. 


*New  York  Agricultural  Experiment  Station,  Bulletin  No.  37,  p.  681. 


Cooling   and   Aeration.  171 

Cooling.— All  that  was  said  in  Chapter  V.  on 
"market  milk,"  in  regard  to  cleanliness  in  di^awing 
the  milk,  applies  eqnally  well  to  milk  that  is  in- 
tended for  cheese  making,  bnt  where  milk  is  made 
into  cheese  it  is  not  necessary,  nor,  indeed,  is 
it  desirable,  that  the  lactic  acid  fermentations  be 
checked  further  than  is  necessary  to  allow  the  milk 
to  come  into  the  cheese  maker's  hands  in  the  best 
condition.  In  cheese  making,  the  fermentations  of 
the  milk  play  a  most  important  part,  and  while  it 
is  not  at  present  known  just  what  fermentations  are 
necessary  or  most  desirable,  sufficient  is  known  to  as- 
sure us  that  a  certain  amount  of  lactic  acid  is  not 
only  desirable  but  necessary  for  the  cheese  making 
process,  and  enough  further  is  known  that  those  fer- 
mentations which  attack  the  protein  substances,  and 
result  in  the  formation  of  strong  flavors,  taints  and 
gases,  are  all  undesirable  in  cheese  making.  For 
the  purpose  of  cheese  making,  it  is  desirable  that  the 
fat  should  separate  from  the  other  constituents  of 
the  milk  as  little  as  possible,  and  to  that  end  the 
previous  treatment  of  the  milk  should  be  such  that 
the  separation  of  cream  will  be  held  back  as  much 
as  possible.  One  of  the  best  means  of  doing  this 
is  to  cool  the  milk  to  the  temperature  of  the  air 
while  it  is  kept  constantl}'  in  motion.  This,  be- 
side helping  to  keep  the  cream  mixed  Avith  the  milk, 
will  also  favor  the  escape  of  any  volatile  animal 
products  that  may  be  present  in  the  milk,  known 
under  the  collective  name  of  animal  odor,  and 
Avhich  would  otherwise  impart  objectionable  flavors 
to    the    cheese. 


172 


MiU'    and    Its  Products. 


Aeration  .—Passing  the  milk  through  an  elevated 
strainer  in  such  a  manner  that  it  may  fall  in 
finely  divided  di'ops  or  streams  through  the  air  be- 
fore it  reaches  the  can,  is  one  of  the  best  means 
of  bringing  about  this  end.  This  is  known  as 
aeration.  It  cannot  be  depended 
upon  to  destroy  or  even  check  the 
germs  of  fermentations  which  may  be 
present  in  the  milk,  beyond  that 
due  to  the  reduction  of  temperature. 
It  is  not  desirable  that  milk  in- 
tended for  cheese  making  should 
be  cooled  much  below  the  tempera- 
ture of  the  air,  and  one  of  the  best 
_  preparations  of  milk  intended  for 
^^^  cheese  making  is  to  allow  it  to 
^^  remain  where  it  will  be  freelv  ex- 
^"S^^  posed  to  a  pure  and  moderately  cool 
Fig.^^I"  H.Mi.kin"  atmosphere.  Under  ordinarj-  condi- 
''eievated  strainer.  tious,  the  milks  of  the  cveuiug  and 
the  succeeding  morning  are  manufactured  together, 
and  the  treatment  indicated  is  naturally  that  of  the 
night's  milk.  It  is  highly  desirable,  however,  that 
the  milk  of  the  morning  should  be  cooled  to  the 
temperature  of  the  atmosphere  before  it  is  taken  to 
the  factory,  and  under  ordinary  conditions  the  milk 
of  the  night  and  morning  should  be  taken  to  the 
factory   in    separate    cans. 

Ripening. — The  lactic  acid  fermentation  is  prob- 
ably one  of  the  most  important  factors  in  all  the 
steps    of   cheese    making,    and   to   know   to   what    ex- 


Rennet    Tests. 


173 


tent  it  has  progressed  before  the  process  begins,  is 
exceedingly  important  to  the  cheese  maker.  To  this 
end,  several  convenient  tests  may  be  applied.  The 
veteran,  who  has  attained  skill  through  long  manip- 
ulation, can  tell  with  a  fair  degree  of  accuracy 
through  the  sense  of  smell  and  taste  the  amount 
of  lactic  acid  present  in  his  milk,  but  this  is  not 
a  safe  enough  guide  for  those  who  are  inexpe- 
rienced, or  those  who  expect  to  make  a  uniform 
product  in  a  uniform 
way  from  day  to  day. 
Rennet  tests. — The 
percentage  of  lactic 
acid  present  in  the 
milk  can  readily  be 
determined  directly  by 
titration  with  a  stand- 
ard alkali,  but  the 
amount  of  lactic  acid 
present  is  also  quite 
readily  dete  r  m  i  n  e  d 
by  the  len  g  t  h  of 
time  required  for  ren- 
net coagulation,  since 
rennet  acts  more 
quickly  upon  milk 
the  riper  it  is,  and 
upon  this  fact  two 
or  three  simple  tests 
have  been  devised,  rig. 
The  simplest  of  these     test  is  made. 


Monrad  rennet  test,     a,  5  c.  c.  pipette; 
graduated   flask;    c,   cup  in  which 


174 


Milk   (Did   Its    Products. 


is  to  add  a  spoouful  of  reunet  of  known  strength 
to  a  teacupful  of  milk  and,  after  stirring  the  two 
together  thoroughly,  to  note  carefully  the  time  re- 
quired for  coagulation.  Another  and  more  exact 
method,  known  as  the  Monrad  test,  is  made  as  fol- 
lows: To  a  measured  quantity  of  milk  at  a  given 
temperature  a  measured  quantity  of  rennet  of  known 
strength  is  added;  ordinarily  the  commercial  rennet  is 
diluted  nine  times  for  this  purpose.  The  rennet  is 
thoroughly  stirred  with  themilk,  and  the  time  re- 
quired for  coagulation  is  carefully  noted.  This  is 
simply  a  development  of  the  cup  test,  and  is  better 
because  of  its  greater  delicacy  and  accuracy;  the 
milk  and  rennet  being  more  carefully  measured,  and, 
diluted   rennet  being  used,  a  wider   range   of   delicacy 

is  reached.  Still 
another  form  of  ren- 
net test,  known  as 
the  Marschall  test, 
has  been  devised. 
In  this  test  the  milk 
is  measured  into  a 
vessel,  one  of  whose 
sides  is  graduated 
and  in  the  bottom 
of  which  there  is  a 
minute  orifice.  The 
rennet  is  added  to 
the  milk,  and  the 
vessel  so  placed  that  the  milk  can  escape  from  the 
hole  in  the  bottom.       So  long    as  the    milk   remains 


Fig.  24.       Marschall  rennet  test. 


Bipening    the   WLUJx.  175 

fluid  the  stream  is  continuous,  but  as  soon  as  the  ren- 
net takes  eifect  and  a  clot  is  formed,  the  stream  stops, 
and  no  more  escapes.  The  number  of  spaces  of  milk 
which  escape  is  taken  as  the  measure  of  the  ripeness 
of  the  milk.  When  the  percentage  of  lactic  acid  is 
great  the  stream  stops  sooner  than  where  little  acid 
has  been  formed,  so  that  in  the  ripe  milk  a  less 
number  of  spaces  shows  upon  the  side  of  the  vessel 
than  in  the  unripe  milk. 

Degree  of  ripeness  necessary. — By  ripeness  of  milk 
for  cheese  making  is  meant,  as  in  the  case  of  but- 
ter making,  the  degree  of  lactic  acid  development  that 
has  taken  place.  For  cheese  making,  the  develop- 
ment of  lactic  acid  should  not  have  proceeded  so 
far  that  the  milk  is  distinctly  sour  to  the  taste,  and 
it  should  have  proceeded  far  enough  so  that  the 
whole  process  of  cheddar  cheese  making,  from  the 
time  of  adding  the  rennet  to  putting  the  cheese  in 
press,  will  take  not  more  than  six  hours.  This  will 
be  indicated  by  a  rennet  test  of  2%  spaces  on  the 
Marschall  apparatus,  or  a  rennet  test  of  one  minute 
on  the  Monrad  test,  when  5  c.  c.  of  diluted  com- 
mercial rennet  extract  (1  part  rennet  to  9  of  water) 
are  added  to  200  c.  c.  of  milk. 

Starters. — In  very  many  cases  the  milk,  when 
brought  to  the  factory,  will  not  be  sufficiently  ripe 
to  give  the  tests  indicated  above.  In  that  case  it 
should  be  allowed  to  ripen  before  the  cheese  making 
process  begins.  This  may  be  brought  about  by 
heating  the  milk  up  to  85°  F.,  when  the  germs 
already    present    become    more    active ;    but  the  time 


176  Milk   and   Its   Products. 

required  for  the  ripening  will  be  shortened,  and  more 
uniform  results  be  obtained  if,  in  addition  to  the 
warming,  an  artificial  starter  is  used.  This  ma\'  be 
an}"  material  containing  the  germs  of  lactic  fermen- 
tation in  active  condition.  The  whey  saved  from 
the  previous  day,  or  milk  naturally  or  artificially 
soured,  may  be  used.  An  extremely  convenient 
form  of  starter  is  made  by  preparing  an  artificial 
ferment  in  the  following  way:  Ten  pounds  of 
whole  milk  are  sterilized  at  180°  F.,  then  cooled  to 
90°,  and  sufficient  commercial  dry  lactic  ferment 
added  to  secure  coagulation  in  twenty -four  hours. 
When  coagulated  this  is  added  to  the  extent  of  10 
per  cent  to  enough  whole  milk  to  make  sufficient 
starter  for  one  day's  use.  The  amount  of  starter 
to  be  added  for  the  purpose  of  ripening  the  milk 
should  be  from  2  to  5  per  cent,  varying  with  the 
temperature  of  the  air  and  the  amount  of  ripeness 
that  it  is  necessary  to  develop  after  the  milk  reaches 
the  factory.  Enough  of  the  ferment  should  be  re- 
served each  day  to  prepare  ferment  for  the  following 
day  from  w^hole  milk;  and  with  care  that  the  ves- 
sels in  w^hich  the  ferment  is  made  are  kept  clean 
and  sweet,  a  single  ferment  may  be  propagated  for 
from  ten  days  to  two  weeks.  Such  a  ferment  will 
give  more  uniform  results,  and  is  less  liable  to  in- 
troduce taints  and  bad  flavors,  than  a  ferment  made 
from  sour  whey,  and  with  a  little  care  and  atten- 
tion, the  fermentation  will  go  on  regularly  from  day 
to  day. 

Rennet.— The    ordinary    source    of    rennet    is    the 


Preparation   of  Rennet.  177 

fourth  or  digestive  stomach  of  a  calf  that  has  not 
yet  ceased  to  live  upon  milk,  though  rennet  is  also 
found  in  the  stomachs  of  puppies  and  pigs,  and  the 
latter  have  occasionally  been  used  as  a  source  of 
rennet.  The  active  principle  of  the  rennet  is  found 
in  the  folds  of  the  lining  membrane  of  the  stomach 
of  the  animal,  and  is  greatest  in  amount  when  a  full 
meal   is   just   digested. 

Rennet  causes  coagulation  of  the  casein  by  con- 
tact, and  is  not  itself  affected  by  the  change.  Its 
action,  however,  is  greatly  modified  by  various  con- 
ditions of  the  milk,  the  most  important  of  which 
are  the  temperature  and  the  condition  of  certain  of 
the  ash  constituents.  Rennet  is  most  active  at  tem- 
peratures near  the  body  heat,  98°  F.  At  temper- 
atures below  80°  F.,  the  action  of  rennet  is  corre- 
spondingly slow.  On  the  other  hand  as  the  temper- 
ature is  raised  above  100°  F.,  the  activity  of  the 
rennet  is  at  first  increased,  but  after  about  130°  F. 
is  reached  the  active  principle  is  rapidly  weakened 
and   finally   destroyed   at   about    140°  F. 

The  activity  of  rennet  is  also  intimately  connected 
with  the  lime  salts  in  the  ash  of  the  milk,  and  par- 
ticularly with  their  condition  as  to  solubility.  The 
presence  of  soluble  salts  of  lime  renders  rennet  much 
more  active,  while  the  insoluble  salts  of  lime  have 
a  correspondingly  retarding  effect.  Thus,  the  develop- 
ment of  lactic  acid  by  rendering  the  lime  salts  more 
soluble  hastens  the  action  of  rennet  on  the  milk.  On 
the  other  hand,  when  milk  is  heated  to  a  tempera- 
ture above  150°  F.  a  part  of  the  lime  salts  are  made 


178  Milk    and    Its    Products. 

insoluble,  and  the  action  of  the  rennet  correspond- 
ingly retarded,  even  though  the  milk  be  again  cooled 
to  a  temperature  at  which  rennet  is  active.  The 
coagulability  of  milk  is  similarly  affected  by  the  addi- 
tion of  any  lime  salt  not  normally  present  in  milk. 
Thus,  if  calcium  oxalate  or  other  insoluble  salt  of 
lime  is  added  to  milk,  the  action  of  rennet  is 
retarded.  On  the  other  hand,  the  addition  of  cal- 
cium chloride  or  other  soluble  salt  is  followed  by  a 
quicker   action   of   the   rennet. 

The  rennet  skin  should  be  obtained  from  an 
animal  of  some  age.  Still-born  calves,  or  calves  less 
than  three  days  old,  furnish  a  rennet  of  very  inferior 
quality.  The  calf  should  be  slaughtered  three  or 
four  hours  after  it  has  had  a  full  meal,  and  the 
fourth  stomach  carefully  taken  out.  This  should  be 
emptied  by  turning  inside  out  and  any  particles 
of  foreign  matter  carefully  picked  off ;  it  should 
not  be  washed  with  water.  It  should  then  be 
sprinkled  with  salt  and  stretched  in  such  a  manner 
that   it   will   readily   dry. 

At  the  present  time  the  preparation  of  the  rennet 
extract  from  the  skins  is  entirely  a  commercial  one, 
and  rennet  so  much  superior,  on  account  of  its 
uniform  strength  and  freedom  from  taints,  is  fur- 
nished in  this  way  that  it  is  not  advisable  to  prepare 
the  rennet  for  use  from  the  skius.  In  the  prepara- 
tion of  the  extract,  the  skins  are  soaked  in  warm 
water  to  which  a  little  salt  has  been  added  until  the 
active  principle  has  been  completely  removed  from 
them.      The  resulting  extract  is  filtered,  and  preserv- 


Separation   of  Whey.  179 

natives,  in  the  shape  of  salt  and  a  little  saltpetre, 
are  added.  Rennet  so  prepared  will  retain  its 
strength  and  purity  for  a  considerable  length  of 
time,  if  kept   in   a   cool,  dark   place. 

Removal  of  tvhey. — After  the  coagulation  of  the 
milk  is  complete  its  constitution  is  as  follows  :  92.5 
parts  soluble,  7.5  parts  insoluble.  The  soluble  por- 
tions are  made  up  of  water  87,  sugar  4.5,  albumin 
.75,  ash  .25.  The  insoluble  are  made  up  of  casein 
3.25,  fat  3.75,  ash  .5.  The  separation  of  these  two 
is  the  chief  task  of  the  cheese  maker,  and  is  brought 
about  partly  by  mechanical  and  partly  by  chemical  or 
physical  agents.  The  chief  mechanical  agents  in 
the  separation  are  cutting  the  curd,  stirring,  and  the 
application  of  pressure.  The  chemical  and  phys- 
ical agents  in  effecting  the  separation  are  :  First, 
application  of  heat ;  second,  development  of  lactic 
acid ;  third,  addition  of  salt ;  fourth,  curing  fermenta- 
tion. These  various  agents  may  be  applied  in  va- 
rious degrees  and  in  various  ways,  all  of  which  have 
a  greater  or  less  effect  upon  the  character  of  the 
resulting  cheese,  producing  an  almost  endless  variety 
of  product.  The  process  that  we  shall  describe  is 
one  in  common  use  in  America,  although  first  prac- 
ticed in  England.  It  it  known  as  the  American 
Cheddar  process,  and  is  a  modification  in  minor  de- 
tails of  the  process  first  employed  at  least  250  j^ears 
ago,  in  the  district  about  the  village  of  Cheddar  in 
Somerset,  England,  from  which  it  takes  its  name, 
and  from  which  it  has  spread  more  or  less  over 
the   whole    world.      Cheddar   cheese    is   still    made    in 


180  Milk   and   Its   Products. 

Somerset,  as  well  as  in  other  parts  of  Great  Britain, 
notably  Ayrshire.  It  is  with  minor  variations  the 
process  most  commonly  employed  in  the  United  States, 
Canada  and  Australia,  and  one  of  its  distinctive  fea- 
tures, namely  the  matting  of  the  curd  after  the  whey 
is  drawn,  is  used  in  making  many  other  varieties 
of  cheese,  as  the  Cheshire,  Leicestershire  and  Derby- 
shire in  England,  the  Edam  and  Gouda  in  Holland, 
and  perhaps   others. 


CHAPTER  XI. 

CHEDDAR    CHEESE    MAKING. 

The  successive  steps  in  the  manufacture  of  Ched- 
dar cheese  may  be  conveniently  grouped  into  seven 
stages  or  periods,  as  follows  :  Period  first,  setting ; 
period  second,  cutting ;  period  third,  heating ;  period 
fourth,  cheddaring  ;  period  fifth,  grinding  ;  period 
sixth,  salting   and   pressing ;    period   seventh,    curing. 

Pernod  I.,  setting. — The  rennet  is  most  active  at 
temperatures  from  near  that  of  the  body,  98°  to 
100°  F.,  up  to  about  130°  F.,  and  if  added  to  the 
milk  at  these  temperatures  will  most  quickly  cause 
coagulation  (p.  177),  but  at  high  temperatures  there 
is  more  tendency  of  the  fat  to  separate,  and  for  this 
reason  the  milk  is  warmed  to  a  degree  sufficient  to 
cause  fairly  rapid  coagulation,  and  at  the  same  time 
not  injure  the  fat.  This  will  vary  from  82°  to  86°  F., 
according  to  conditions.  The  milk,  when  brought  to 
the  factory,  is  collected  in  the  vats  and  the  whole 
mass  gradually  warmed  up  to  the  proper  tempera- 
ture, with  frequent  gentle  stirring  to  prevent  any 
separation  of  the  fat  in  the  form  of  cream.  When 
the  whole  mass  is  warmed  up  to  82°  the  milk  is 
tested  for  ripeness,  and  if  sufficiently  ripe  the  ren- 
net   is    added    at   once,    but   if    the    milk    is    insuffi- 

(181) 


182  Milk   and   Its   Products. 

cieutly  ripe  a  starter  is  then  added,  and  the  milk 
allowed  to  stand  at  this  temperature  until  a  suffi- 
cient amount  of  acid  has  developed,  care  being 
taken  that  it  is  frequently  stirred  and  no  cream 
allowed   to   rise. 

The  rennet  should  be  added  in  sufficient  quan- 
tity to  cause  the  milk  to  coagulate  in  from  ten  to 
fifteen  minutes,  and  to  be  ready  for  the  knife  in 
from  thirty  to  thirty -five  minutes.  It  was  formerly 
supposed  that  the  amount  of  rennet  added  had  an 
effect  upon  the  whole  process  of  manufacture,  and 
particularly  upon  the  curing  fermentation,  but  while 
the  matter  is  still  unsettled,  later  researches  go  to 
show  that  the  influence  of  the  rennet  upon  the 
curing  is  probably  very  slight.  The  amount  of  ren- 
net to  be  used  will  also  vary  with  the  strength  of  the 
extract  ;  two  to  three  fluid  ounces  of  rennet,  of  or- 
dinary strength,  per  thousand  pounds  of  milk  is 
sufficient.  The  rennet  should  be  added  to  the  milk 
in  such  a  way  that  the  coagulation  will  be  uniform 
throughout  the  whole  mass.  If  the  rennet  is  added 
in  full  strength  and  at  a  high  temperature,  the 
milk  will  be  immediately  curdled  as  soon  as  the 
particles  of  rennet  come  in  contact  with  it,  and 
coagulation  will  begin  in  part  of  the  mass  before 
the  rennet  can  be  thoroughly  united  with  the  whole 
body  of  milk.  The  rennet  should  be  diluted  with 
twenty  to  fifty  times  its  own  bulk  of  cold  water. 
The  dilution  renders  the  uniform  mingling  of  the 
rennet  with  the  milk  easier,  and  the  cold  water 
keeps  it  inactive  until  it  has   been   warmed  up  to  the 


Setting   and    Cutting.  183 

temperature  of  the  milk.  So  soon  as  the  rennet  is 
added,  the  milk  should  be  quickly  and  carefully 
stirred,  so  that  the  rennet  may  be  uniformly  mingled 
with  every  part  of  it.  This  stirring  should  continue 
until  the  mixture  of  rennet  and  milk  is  complete, 
but  should  stop  before  any  appearance  of  coagula- 
tion. The  milk  in  the  vat  is  then  allowed  to  be- 
come quiet,  and  remains  undisturbed  while  the  pro- 
cess of  coagulation  is  going  on,  the  object  being  to 
secure  a  uniformly  solid  clot  or  eoagulum  through 
the  mass.  The  action  of  the  rennet  is  not  instanta- 
neous ;  the  first  appearance  of  coagulation  is  noticed 
by  a  slight  thickening  of  the  milk.  This  gradually 
increases  until  the  whole  mass  is  solid,  and  if  left 
undisturbed  the  action  of  the  rennet  continues  to 
contract  the  coagulated  casein  and  cause  a  partial 
separation  of  the  whey.  As  soon  as  the  coagulation 
is  strong  enough,  so  that  the  casein  will  maintain 
its  shape  when  broken,  the  contents  of  the  vat  are 
ready  for  the  next  step  in  the  process. 

Period  II.,  cutting. — The  curd,  as  the  coagulated 
casein  is  called,  is  ready  for  cutting  when  under 
strain  it  will  break  with  a  clean  fracture.  This  is 
conveniently  tested  by  gently  inserting  the  finger  in 
the  curd  in  an  oblique  position  and  slightly  raising 
it,  when  if  the  curd  breaks  clean  across  the  finger 
it  is  sufficiently  firm  for  cutting.  Cutting  is  per- 
formed in  order  to  facilitate  the  further  contraction 
of  the  casein  and  the  expulsion  of  the  whey.  For- 
merly the  solid  mass  of  curd  was  broken  up  into 
small    pieces    by    any    sort    of    an     instrument    that 


184  Milk  and  Its  Products. 

might  be  at  hand,  or  simply  with  the  fingers,  no 
care  being  taken  that  the  pieces  of  curd  should  be 
of  uniform  shape  or  size,  but  now  gangs  of  steel 
knives,  in  one  of  which  the  blades  are  arranged 
horizontally  and  the  other  perpendicularly,  are  used 
to  cut  the  mass  of  curd  into  cubes  of  about  %  of 
an  inch  in  diameter.  The  fat  is  retained  in  the 
cheese  by  being  enclosed  in  the  meshes  of  the  casein, 
and  in  breaking  up  the  mass  of  casein,  a  certain 
number  of  fat  globules  is  always  set  free.  The 
care  with  which  the  cutting  and  subsequent  hand- 
ling of  the  curd  is  done  controls  the  loss  of  fat 
through  this  source.  Formerly,  the  mass  of  curd 
was  allowed  to  become  very  firm  before  cutting,  but 
the  more  recent  practice  has  shown  that  the  best 
results  in  expelling  the  whey  from  the  curd  are 
reached  when  the  curd  is  cut,  so  soon  as  it  has 
sufficiently  coagulated  to  maintain  its  form.  The 
curd  is  cut  by  passing  the  horizontal  knife  through 
the  vat,  usually  in  a  longitudinal  direction,  and  then 
by  passing  the  perpendicular  knife  both  longitudi- 
nally and  crosswise  of  the  vat.  It  is  immaterial 
whether  the  horizontal  or  perpendicular  knives  are 
used  first.  Some  skilled  cheese  -  makers  prefer  the 
one  practice  and  some  the  other.  The  object  to  be 
attained  is  to  break  up  the  curd  into  as  uniform 
a  mass  of  kernels  as  possible,  or,  in  the  language 
of  the  cheese -maker,  to  secure  an  "even  cut."  After 
the  curd  is  cut,  the  whey  begins  to  escape,  and  the 
curd  sinks  to  the  bottom  of  the  vat.  If  allowed  to 
remain   undisturbed,  the  cut   surfaces  of   the   particles 


Heating   or    Cooking.  185 

of  curd  readily  unite,  and  in  breaking  them  apart 
again  more  fat  is  lost.  Hence  as  soon  as  the  curd 
is  cut,  gentle  agitation  of  the  whole  mass  should 
begin.  This  agitation  should  be  sufficient  to  cause 
the  particles  to  move  upon  one  another,  but  not 
violent  enough  to  break  them  up.  The  curd  rapidly 
shrinks  and  hardens  ;  more  rapidly  upon  the  outside 
than  the  inside.  This  soon  results  in  the  formation 
of  a  so-called  "membrane,"  which  not  only  tends 
to  prevent  the  particles  from  sticking  together,  but 
affords  some  resistance  to  further  breaking  up.  This 
"membrane"  is  pervious  to  water,  but  retains  the 
globules  of  fat  ;  so  as  soon  as  the  contraction  has 
reached  this  point,  or  when  the  curd  is  well  "healed 
over,"  the  further  expulsion  of  the  water  should  be 
aided  by  heat,  and  this  point  begins  the  third  step. 
Period  III.,  heating  or  cooking. — The  term  "cook- 
ing," as  applied  to  the  manufacture  of  cheese,  is  a 
misnomer  so  far  as  it  relates  to  any  change  in  the 
composition  or  condition  of  the  material  through 
the  effect  of  heat.  By  cooking  any  ordinary  sub- 
stance is  meant  the  application  of  a  degree  of  heat 
sufficient  to  cause  a  coagulation  of  albuminous  sub- 
stances or  a  breaking  down  of  starchy  ones.  The 
degree  of  heat  used  in  cheese  making  during  this 
stage  never  reaches  anywhere  near  this  point,  and 
never,  except  in  rare  instances,  is  a  temperature  of 
blood  heat  exceeded.  The  change  to  be  brought  about 
in  this  process  is  wholly  the  contraction  of  the  curd 
and  the  consequent  expulsion  of  water  from  within 
the   particles.      To   this   end   the   heat   serves   a   two- 


186  Milk   and   Its   Products. 

fold  and  important  part.  The  curd  is  contracted  to 
some  extent  by  the  action  of  the  rennet  still  con- 
tinuing ;  also  to  some  extent  by  the  direct  applica- 
tion of  the  heat,  but  to  a  greater  extent  by  the 
effect  of  lactic  acid  upon  the  curd,  the  production 
of  lactic  acid  being  greatly  favored  by  the  increased 
temperature.  It  is  desu-able  that  this  contraction  of 
the  curd  in  the  cooking  stage  go  on  uniformly  through- 
out the  whole  mass.  The  heat  is  therefore  applied 
gradually  and  with  constant  stirring.  As  the  parti- 
cles of  curd  shrink  in  size,  the  tendency  for  them 
to  unite  in  masses  constantly  diminishes,  and  they 
are  broken  with  greater  difficulty,  so  that  while  at 
first  extreme  care  is  necessary  to  prevent  the  par- 
ticles of  curd  from  becoming  broken,  as  the  temper- 
ature rises,  the  stirring  may  become  more  rapid  and 
vigorous.  The  heat  should  be  raised  slowly  from 
the  setting  point  of  the  milk  up  to  98°  F.,  and  it 
should  not  be  more  rapid  than  2°  in  five  mmutes; 
and  unless  the  lactic  acid  develops  very  rapidly  it 
is  better  to  take  even  more  time  than  this.  When 
the  temperature  of  98°  F.  is  reached,  the  stirring 
may  cease  and  the  particles  of  curd  be  allowed  to 
settle  upon  the  bottom  of  the  vat  until  the  curd  is 
thoroughly  shrunken  and  a  sufficient  amount  of 
lactic  acid  has  been  developed.  At  the  end  of  the 
cooking  stage  the  particles  of  curd  should  have 
shrunken  to  less  than  one -half  of  their  former  size, 
and  should  have  become  so  hard  that  when  pressed 
together  between  the  hands,  and  the  pressure  sud- 
denly   relaxed,  they    will    fall    apart,    and     show    no 


Cheddaring   or  Matting.  187 

tendency  to  stick  togetlier.  By  this  time  there  should 
have  developed  a  sufficient  amount  of  lactic  acid  so 
that  the  curd  will  draw  out  in  fine  threads  a 
quarter  of  an  inch  long  when  applied  to  the  hot 
iron. 

When  the  curd  has  reached  the  highest  temper- 
ature, it  may  be  allowed  to  settle,  and  a  part  of  the 
whey  may  be  drawn  off  the  top  of  the  vat.  This 
is  of  advantage  particularly  when  the  development 
of  lactic  acid  is  likely  to  be  rapid,  and  it  is  de- 
sirable to  separate  the  whey  from  the  curd  in  a  very 
short  time,  but  sufficient  whey  should  be  left  to 
cover  all  of  the*  curd  two  or  three  inches  deep 
until  sufficient  acid  has  been  developed  for  the 
cheddaring   process. 

Period  IV.,  cheddaring,  or  matting.  — When  suffi- 
cient acid  has  developed  in  the  whey,  it  is  di-awn 
off  from  the  vat  through  the  gate  or  by  means 
of  a  syphon.  The  curd  is  then  allowed  to  mat 
together  into  a  mass,  which  is  the  distinctive  fea- 
ture of  the  Cheddar  process.  This  matting  together 
may  be  done  either  in  the  vat  or  in  a  special 
vessel,  called  a  curd  sink.  In  the  former  case, 
when  all  the  whey  is  run  off  the  particles  of  curd 
are  brought  together  upon  the  two  sides  of  the  vat 
and  a  channel  opened  between  them,  so  that  any 
whey  held  by  the  particles  of  curd  may  be  al- 
lowed to  escape.  When  the  particles  of  curd  are 
sufficiently  matted  together  to  maintain  themselves  in- 
tact, the  mass  is  cut  up  into  blocks  about  8x8x12 
inches,    and    these    blocks   are    turned    over    so    that 


188  Milk   and   Its   Products. 

the  part  that  was  uppermost  comes  in  contact  with 
the  bottom  of  the  vat.  A  further  draining  of  the 
whey  takes  place,  and  the  blocks  of  curd  are  next 
piled  upon  one  another  two  deep,  care  being  taken 
in  forming  these  piles  that  the  parts  that  were  ex- 
posed to  the  air  are  turned  in.  Later  on  the  curd 
is  piled  again  in  still  deeper  piles,  and  as  the  pro- 
cess continues  the  mass  is  piled  over  and  over 
again,  care  being  taken  that  the  exposed  parts  of  one 
pile  are  put  into  the  interior  of  the  succeeding,  so 
that  the  heat  may  be  uniform  throughout  the  whole 
mass.  In  the  curd  sink  the  manipulation  is  not 
essentially  different.  The  curd  .sink  is  a  square 
wooden  receptacle  fitted  with  a  false  slatted  bottom 
and  covered  with  coarse  cotton  or  linen  cloth, 
through  which  the  whey  can  easily  escape.  When 
the  time  comes  for  separating  the  whey,  so  much 
as  will  run  off  readily  is  drawn  off,  and  the  re- 
maining whey,  mixed  with  particles  of  curd,  is 
dipped  into  the  sink,  the  whey  runs  off  freely 
through  the  strainer  and  slatted  bottom,  and  the 
curd,  being  spread  over  the  whole  surface  of 
the  sink,  soon  mats  into  a  solid  mass,  and  the 
piling  process  goes  on  the  same  way  as  is  done 
in  the  vat.  During  this  process  various  changes 
take  place.  The  pressure  of  the  particles  of  curd 
upon  one  another  serves  to  expel  a  large  part  of 
the  whey  that  still  remains ;  at  the  same  time  the 
temperature  is  kept  sufficiently  high  so  that  the 
production  of  lactic  acid  is  not  checked.  The  effect 
of   the   acid   is   to  cause   a   series   of   marked   changes 


Grinding. 


189 


in  the  physical  condition  of  the  curd.  From  the 
condition  of  a  tough,  spongy  mass  when  first  ched- 
dared,  the  curd  changes  into  a  smooth,  elastic, 
fibrous  condition,  not  unlike  the  physical  appearance 
of  well  cooked,  lean  meat.  When  the  curd  reaches 
the  condition  above  described  it  is  ready  for  the 
next  step  in  the  process,  and  by  this  time  sufficient 
lactic  acid  will  have  developed  so  that  fine  threads 
may  be  drawn  out  two  to  three  inches  on  a  hot 
iron. 

Period   V.,  grinding  .—When  the  curd   is  ready   for 
grinding,    the    whey    has    been    removed  to    so     great 

an  extent  that  the  pro- 
duction   of    lactic    acid 
measurably  stops.     The 
curd    is   ground  in   or- 
der   to    reduce     it     to 
particles   of  convenient 
size    for    receiving    the 
salt    and    for    pressing 
into    a    solid    mass    in 
the  cheese.     The  grind- 
ing,   or    more   properly 
the    cutting,  is  done  in 
special  machines  known 
as   curd  mills.      Of  the 
various    styles    of    mills,    those    are    best    which   cut 
the  curd  into   pieces  of   uniform  size,  without   tearing 
it  apart,  for   the  reason   that  when  so  treated   less  fat 
escapes  and  the   uniformity  of  size  of  the  pieces  aids 
in  the   proper   and  even  absorption  of  the  salt  by  the 


Fig.  25.     "Harris"  curd  mill. 


190 


Milk   and   Its   Products. 


curd.    After  the  curd  is  ground,  it  is  kept  sufficiently 
stirred   to   keep   the   particles    from   matting   together 


Fig.  26.     "  MacPherson"'  curd  mill. 

again.  A  further  maturing  of  the  curd  takes  place, 
during  which  it  takes  on  a  peculiar  nutty  flavor, 
and  the  particles  of  casein  begin  to  break  down 
so  that  the  fat  may  be  re- 
moved by  pressure.  When 
this  stage  is  reached  the  curd 
is  ready  for  the  next  step, 
which  is  salting. 

Period  VI.,  salting. — Salt  is 
added  to  the  curd  primarily  for 
the  sake  of  the  flavor  it  im- 
parts to  the  cheese,  just  as 
salt  is  added  to  butter:  but  the 
addition  of  the  salt  to  the  curd 
has  a  further  effect  in  the  pro- 
cess of  manufacture.  The  salt 
makes  the  curd  drier  by  reason  of  extracting  the 
water  for   its    own   solution,    and    at   the    same   time 


Pohl" 


Salting   and   Pressing.  191 

hardens  the  curd.  It  also  checks  the  further  devel- 
opment of  lactic  acid.  The  salt  should  be  uniformly 
mixed  through  the  curd,  and  the  curd  kept  stirred 
until  it  is  full}^  dissolved.  A  salt  of  rather  coarse 
grain  is  preferable  for  cheese.  It  requires  a  some- 
what longer  time  for  solution,  and  the  particles  of 
the  salt  are  carried  to  the  centre  of  the  pieces  of 
curd  more  effectually.  When  the  salt  is  thoroughly 
dissolved  the   curd  is  ready   to  put   in  the   press. 

During  the  cheddaring  and  grinding  stage  va- 
rious means,  as  covering  with  cloths,  etc.,  have 
been  taken  to  keep  up  the  temperature  of  the  curd, 
and  at  the  time  when  the  cheese  is  ready  to  salt 
it  should  not  be  below  90°  F.  When  the  salt  is 
added  the  curd  should  be  spread  out  thin,  so  that 
it  will  cool  off,  and  when  it  is  put  into  the  press 
should  be  at  a  temperature  of  from  78°  to  82°  F. 
If  the  curd  is  put  in  the  press  too  warm,  the  fat 
is  more  easily  pressed  out  and  lost.  On  the  other 
hand,  if  the  curd  is  at  too  low  a  temperature  when 
put  in  the  press,  it  is  more  difficult  to  make  the 
particles  adhere  together  into  a  solid  mass.  The 
object  of  pressing  the  cheese  is  to  bring  it  into  a 
form  suitable  for  transportation  and  convenient  for 
consumption.  The  pressure  also  removes  any  surplus 
moisture  that  is  in  the  curd ;  but  the  primary  object 
of  pressing  is  not  to  remove  moisture.  In  fact,  all 
of  the  moisture  that  is  removed  from  the  cheese  by 
the  press  is  that  held  by  capillarity  between  the  par- 
ticles of  curd,  and  practically  none  can  be  expressed 
from   the   particles    themselves.      If  the   curd   is  too 


192 


Milk   and   Its  Products. 


wet  at  this  stage,  it  is  because  care  was  not  taken 
to  expel  the  moisture  from  the  particles  of  the 
curd  in  the  cooking  process,  and  it  cannot  be  re- 
moved  by    extra    pressure.       An    ideal     condition    of 


Fig.  28.     "  Fraser"  cotitinuous  pressure  gang  cheese  press. 


the  cheese  is  to  so  press  it  that  the  particles  will 
unite  together  in  as  nearly  as  may  be  a  solid 
mass.  This  will  depend  upon  the  temperature  and 
maturity  of  the  curd.  If  the  curd  is  put  in  press 
at  the  stage  of  maturity  corresponding  to  the 
beginning  of  the  cheddaring  period,  it  will  be 
very  difficult  to  cause  it  to  unite  in  a  firm  mass  ; 
but  if  it  is  allowed  to  mature  until  the  casein 
shows    signs     of     breaking    down,    and    then     is   not 


Curing.  193 

lower  than  78°  F.,  a  slight  amount  of  pressure 
will  cause  the  particles  to  unite  in  a  smooth  and 
solid  mass.  The  pressure  should  be  uniform  and 
continuous  for  at  least  twenty  hours.  Where  a 
screw  press  is  used,  care  must  be  taken  to  tighten 
the  screws  as  rapidly  as  they  become  loose,  partic- 
ularly for  the  first  hour  after  the  cheese  is  put  in 
the  press.  Those  presses  that  are  fitted  with  ap- 
pliances for  taking  up  the  slack  and  making  the 
pressure  continuous  show  excellent  results  in  the 
texture  of  the  cheese.  After  the  cheese  has  been 
in  the  press  for  three -fourths  of  an  hour  it  should 
be  taken  out,  turned,  the  bandage  straightened,  and 
the  whole  cheese  wij)ed  with  a  cloth  wrung  out  of 
water  as  hot  as  can  be  borne  by  the  hand.  This 
warming  of  the  surface  aids  in  the  formation  of  a 
firm,  transparent  rind,  and  it  improves  the  appear- 
ance of  the  cured  cheese.  Seamless  bandage  is 
practically  the  only  kind  now  used,  and  it  should 
be  cut  of  such  a  length  that  it  will  extend  over 
each  end  of  the  cheese  for  an  inch  and  a  half  or 
two  inches  ;  when  the  cheese  is  put  in  the  press, 
circular  cap  cloths  should  be  put  between  the  ends 
of  the  cheese  and  the  follower.  These  cap  cloths  are 
allowed  to  remain  upon  the  cheese  after  it  is  taken 
from  the  press  and  while  it  is  curing,  and  are  re- 
moved  just   before   the  cheese  is   boxed   for  market. 

Period  VII.,  curing. — The  green  cheese,  when 
taken  from  the  press,  if  exposed  to  a  temperature 
of  about  70°  in  a  pure  atmosphere,  undergoes  a 
series    of     fermentations     which     result     in     breaking 


194  Milk    and   Its    Products. 

down  or  rendering  soluble  the  casein  and  in  the 
development  of  the  characteristic  flavors  peculiar  to 
good  cheese.  These  flavors  are  almost  entirely  de- 
veloped during  the  ripening  process.  The  ripening 
is  brought  about  by  a  series  of  fermentations  that 
goes  on  in  the  cheese.  It  is  not  well  understood 
just  what  these  fermentations  are ;  but  it  seems 
evident  that  at  least  in  the  early  stages  of  the 
curing,  lactic  acid  germs  are  active,  although  the 
greater  majority  of  these  disappear  after  a  short 
time.  During  the  ripening  process,  oxygen  is  taken 
up  and  carbonic  acid  given  off.  The  quality  of 
the  cheese  is  best  when  the  ripening  process  goes 
on  graduall}^  and  continually.  The  higher  the  tem- 
perature the  faster  the  ripening  will  go  on  ;  an 
extreme  temperature  of  65°  or  70°  giving  the  best 
results.  At  the  end  of  from  four  to  six  weeks  the 
casein  will  be  so  broken  down  that  the  cheese  is 
fairly  digestible  and  fit  for  consumption,  though  if 
kept  longer  under  good  conditions  the  cheese  will 
improve  for  three  or  four  months,  and  then  if  kept 
moderately  cool,  and  in  not  too  moist  nor  too  dry 
an  atmosphere,  it  may  be  kept  one  or  two  years. 
During  the  early  part  of  the  curing  process  the 
cheeses  should  be  turned  upon  the  shelves  every  day 
until  a  sufficient  amount  of  water  has  evaporated, 
so  that  they  no  longer  tend  to  lose  their  shape. 
Difficulties  Wkely  to  occur  in  cheddar  cheese  mak- 
ing.—  The  chief  difficulty  in  cheddar  cheese  making 
comes  from  the  presence  in  the  milk  of  germs 
which    produce    fermentations     that    are    undesirable. 


* ^  Gassy  ^^   Curds.  195 

These  fermentations  usually  begin  during  the  cook- 
ing process,  and  continue  through  cheddaring.  Or- 
dinarily they  evolve  a  considerable  amount  of  gas, 
causing  what  are  known  as  floating  or  gassy  curds, 
and  are  usually  accompanied  by  disagreeable  odors 
and  flavors.  The  formation  of  the  gas  in  the  curd 
gives  it  a  sponge -like  texture,  and  when  the  par- 
ticles of  curd  are  cut  across  they  are  seen  to  be 
full  of  minute  holes,  the  condition  usually  denom- 
inated pin-holes.  The  best  means  of  treating  this 
trouble  is,  of  course,  prevention;  but  even  with  the 
utmost  care  by  makers  of  experience,  milk  contain- 
ing the  germs  of  these  fermentations  will  find  its 
way  into   the   vat. 

In  many  cases  the  trouble  from  gassy  and  tainted 
milk  is  caused  by  the  milk  of  one  or  two  dairies, 
and  in  exceptional  cases  the  milk  of  a  siagle  cow 
may  infect  a  whole  vat.  The  particular  dairies  or 
even  cows  that  are  causing  the  trouble  may  usually  be 
detected  by  employing  one  of  the  fermentation  tests 
described  in  Appendix  A.  Ordinarily  these  fermenta- 
tions do  not  work  with  the  lactic  fermentation  ;  each 
hinders  the  action  of  the  other  so  that  the  chief 
means  of  overcoming  the  difficulty  of  gas  or  pin-hole 
curds  is  to  favor  in  every  way  possible  the  pro- 
duction of  lactic  acid.  To  this  end  the  milk  is 
well  ripened  before  the  rennet  is  added,  and  the 
heat  is  raised  as  rapidly  as  possible  to  a  higher 
temperature  of  cooking  than  ordinarily  is  used.  In 
extreme  cases  the  curds  may  be  heated  as  high 
as    104°   F.     After   the    whey   has    been   drawn    great 


196  Milk   mid    Its   Products. 

care  is  taken  to  keep  the  temperature  of  the  curd 
from  falling,  and  at  the  same  time  the  escape  of 
the  gas  is  favored  by  frequent  turning  and  piling 
of  the  curd.  Where  the  curds  are  gassy  the  ched- 
daring  process  must  be  continued  until  the  formation 
of  gas  has  ceased  and  the  holes  in  the  curd  have 
collapsed.  In  extreme  cases,  where  the  gassy  curds 
have  produced  very  strong,  undesirable  flavors,  these 
may  be  removed  by  drenching  with  hot  water.  The 
means  used  to  prevent  the  devf^lopment  of  gas,  and 
to  get  rid  of  the  gas  already  formed,  ordinarily  favor 
the  escape  of  fat  from  the  cheese,  so  that  while  the 
bad  effects  of  the  gassy  curd  may  be  largely  elimi- 
nated from  the  finished  cheese,  still  it  is  always  done 
at   the    expense    of    a    certain    loss    of    fat. 

Another  difficulty  that  often  confronts  the  cheese- 
maker  is  that  coming  from  the  milk  arriving  in  too 
ripe  a  condition,  not  necessarily  accompanied  by  un- 
desirable fermentations.  In  the  case  of  such  milk, 
the  development  of  lactic  acid  is  very  rapid  and  the 
curds,  technically  described,  "work  fast."  When  this 
occurs,  the  production  of  lactic  acid  is  more  rapid 
than  the  shrinking  of  the  curd,  and  the  whey  is 
sufficiently  acid  to  be  drawn  off  before  the  curd  has 
shrunken  down.  In  this  case,  the  curd  should  be 
thoroughly  and  continually  stirred  after  the  whey 
is  drawn  until  the  whey  has  been  well  worked  out 
before  the  curd  is  allowed  to  cheddar ;  but  where 
it  is  known  at  the  beginning  of  the  process  that 
the  milk  is  over -ripe,  care  should  be  taken  through- 
out   the    whole    process    to   use   every   means    to    re- 


Flavor   and    Texture.  197 

tard  the  formation  of  lactic  acid,  and  at  the  same 
time  to  cause  as  rapid  a  shrinking  of  the  curd  as 
possible.  To  this  end,  the  milk  may  be  set  at  a 
lower  temperature  and  a  larger  amount  of  rennet 
used,  and  when  the  curd  is  cut  it  should  be  stirred 
until  the  whey  has  well  separated  before  the  heat- 
ing process  begins.  With  care  in  these  particulars, 
there  is  slight  danger  of  the  formation  of  acid  be- 
fore  the    curd   has    shrunken    down. 

Qualities  of  cheese.  — A  well  cured  cheddar  cheese 
of  good  quality  should  have  about  the  following 
composition : 

Per  cent. 

Water 34. 

Fat 36.8 

Casein  and  albumin - 25.7 

Sugar,  asti,  etc.  (largely  salt) 3.5 

100. 

The  characteristic  flavors  should  be  well  pro- 
nounced but  not  strong,  depending  somewhat  upon 
the  age  of  the  cheese.  The  flavor  should  also  be 
cleaii  r  that  is,  free  from  any  flavors  due  to  the 
influence  of  undesirable  fermentations  or  to  foreign 
matters  that  may  have  gained  access  to  the  milk 
through  the  food  or  otherwise.  The  texture  should 
be  solid,  smooth  and  firm.  When  bored  with  the 
trier,  the  plug  should  come  out  solid,  or  nearly  so, 
and  smooth.  There  should  be  no  moisture  visible 
in  any  part,  and  no  appearance  of  any  separation 
of  the  fat  from  the  casein.  When  crushed,  the  cheese 
should  readily  break  down  into  a  smooth,  unctuous 
mass,  without    indication   of    the    presence    of    undue 


198  Milk   and    Its   Products. 

moisture,  and  should  emit  a  pleasant,  nutty  flavor. 
When  broken  across,  the  flaky  texture  should  be 
manifest,  the  so-called  "flinty  break."  The  color 
should  be  uniform,  not  mottled,  and  with  more  or 
less  of  a  tendency  to  translucence,  especially  in  new 
uncolored  cheese.  The  rind  should  be  smooth,  with- 
out cracks,  hard  and  transparent.  The  bandage 
should  extend  evenly  over  the  ends  of  the  cheese  for 
about  two  inches  and  should  be  straight  and  smooth. 
The  ends  of  the  cheese  should  be  parallel  and  the 
sides  straight.  These  various  qualities  are  usually 
ranked   according   to   the   following   scale  : 

Per  cent. 

Flavor    45 

Texture 35 

Color 15 

Finish 5 

100 


CHAPTER  XII. 

OTHER    VARIETIES    OF    CHEESE. 

Slight  variations  in  any  of  the  minor  details  of 
the  cheese  making  processes  have  a  distinct  influence 
on  the  character  of  the  finished  product.  A  natural 
result  of  this  is  that  the  varieties  of  cheese  are 
almost  innumerable.  Von  Klenze*  in  his  Hand  Book 
of  Cheese  Technology  describes  no  less  than  156  dif- 
ferent kinds,  whose  manufacture  is  distributed  through 
Europe  and  America.  Not  only  is  the  number  of  dis- 
tinct kinds  very  large,  but  the  same  kind  or  variety 
varies  greatly  in  character  and  quality,  according  to 
the  conditions  under  which  it  is  made.  Without  at- 
tempting to  accurately  classify  the  various  kinds  of 
cheese,  it  may  be  said  that  they  fall  roughly  into 
about  three  natural  groups  or  classes.  First,  those 
whose  chief  characteristics  depend  upon  the  amount 
of  water  that  has  been  removed  in  the  process  of 
manufacture.  These  we  may  call  hard  or  soft  cheeses. 
Second,  those  whose  distinctive  qualities  depend  upon 
the  amount  of  fat  which  the  cheese  contains,  whether 
it  is  the  normal  amount  of  the  milk,  whether  a  part 
of     the    fat    has    been    removed,  as    in    the    case    of 

*Von  Klenze,  Handbuch  der  Kaserei-Technik,  Bremen,  1884. 
(199) 


200  Milk   and  Its    Products. 

skimmed  or  partially  skimmed  cheeses,  or  whether  fat 
has  been  added  to  the  milk  as  in  the  case  of  the  so- 
called  cream  cheeses.  And  third,  those  whose  dis- 
tinctive characteristics  depend  upon  the  sort  of  fer- 
mentation to  which  they  have  been  subjected.  In 
the  case  of  many  of  these,  special  ferments  are  in- 
troduced into  the  cheese  during  the  curing  process,  to 
bring  about  the  desired  characteristics  and  flavors. 
The  details  of  manufacture  upon  which  the  peculiar 
characters  depend  are,  in  many  cases,  so  intricate 
and  minute  that  it  is  practically  impossible  to  so 
describe  them  that  a  novice  might  successfully  fol- 
low out  the  directions.  The  actual  practice  must  in 
most  cases  be  learned  at  the  hands  of  an  expe- 
rienced teacher.  Even  as  careful  a  description  as 
possible  is  more  than  could  be  attempted  here,  and 
we  shall,  therefore,  limit  our  discussion  to  a  few  of 
the  better  known  and  most  largely  manufactured 
varieties.  The  introduction  of  the  so-called  fancy 
varieties  in  America  is  in  its  infancy,  but  is  rapidly 
developing,  and  bids  fair  to  become  a  most  impor- 
tant   diversification    of    the    dairy    industry. 

American  home-trade,  or  stlrred-ctird  cheese. — The 
popular  consumptive  demand  of  most  American  mar- 
kets requires  a  softer  and  milder  flavored  cheese 
than  the  cheddar  or  export  type.  This  is  brought 
about  by  incorporating  a  larger  amount  of  water  with 
the  curd,  and  by  hastening  the  curing  process,  and 
not  curing  it  so  far  as  is  ordinarily  done  with  a  well- 
ripened  cheddar.  The  details  of  the  manufacture  of 
the  American   home -trade  and  the  American   cheddar 


''Home -Trade,''  or  ''Stirred- Curd.''  201 

or  export  are  in  the  main  similar.  In  fact,  the  two 
processes  merge  into  one  another  in  such  a  way  that 
we  find  a  regular  gradation  in  the  cheese  from  the 
softest,  mildest,  short -keeping  stirred -curd  cheese  on 
the  one  hand  to  the  most  solid,  long-keeping  ched- 
dar  on  the  other.  The  distinctive  differences  in  the 
two  processes  of  manufacture  are  that  in  the  home- 
trade  cheese,  after  the  whey  is  drawn  from  the  curd, 
the  curd  is  not  allowed  to  mat  into  a  mass  or  Ched- 
dar, but  is  kept  stirred  in  such  a  way  that  the  whey 
will  drain  off  until  it  is  dry  enough  so  that  the  par- 
ticles of  curd  will  not  unite.  It  is  then  salted  and, 
with  more  or  less  further  maturing  of  the  curd,  is 
pressed  and  cured.  The  character  of  the  resulting 
cheese,  however,  depends  quite  as  much  upon  the 
amount  and  character  of  the  changes  that  go  on  in 
the  curd  after  the  whey  is  drawn,  and  before  it  is 
put  into  press,  as  upon  the  mere  fact  of  allowing  it 
to  pack  in  a  mass  (cheddar)  or  keeping  it  apart  by 
stirring.  If  the  cheddar  variety  is  ground  shortly  after 
matting:,  and  immediately  salted  and  put  to  press, 
the  resulting  cheese  will  resemble  the  stirred -curd 
type.  On  the  other  hand,  if  the  stirred -curd  is  kept 
warm  and  frequently  stirred,  many  of  the  same 
changes  will  go  on  as  in  the  cheddared  curd,  and 
the  cheese  when  cured  will  resemble  the  cheddar 
type. 

Another  distinction  between  the  two  processes  is 
that  in  the  case  of  the  cheddar  cheese  the  aim  is  to 
get  rid  of  all  the  water  consistent  with  a  compact 
union   of  the  particles   of   casein.        In   the  manufac- 


202  Milk  and    Its    Products. 

ture  of  the  stirred -curd  cheese,  on  the  other  hand, 
the  aim  is  to  retain  as  much  water  as  possible 
without  having  it  appear  in  the  form  of  free  water  in 
the  cheese.  To  this  end,  in  the  stii-red-curd  process 
those  influences  which  tend  to  contract  the  curd, 
namely,  the  application  of  heat  and  the  development 
of  lactic  acid,  are  not  carried  so  far  as  in  the  Ched- 
dar process.  In  fact,  in  many  cases  they  are  not  car- 
ried far  enough  to  remove  all  of  the  water  necessary, 
and  some  remains  in  the  cheese,  making  a  "wet," 
*' sloppy''  or  "leaky"  cheese. 

Because  of  the  larger  amount  of  water  it  contains, 
this  kind  of  cheese  is  profitable  to  the  producer  of 
the  milk  and  to  the  manufacturer,  and  when  properly 
made  and  carefully  cured,  it  may  be  of  excellent 
quality,  being  mild,  creamy  and  soft  ;  but  largely, 
too,  because  of  the  large  amount  of  water  contained 
in  it,  it  is  easily  subject  to  decomposition  changes, 
goes  off  flavor  rapidly,  and  does  not  bear  transporta- 
tion well. 

Sage  cheese. — In  many  parts  of  the  United  States 
this  cheese  is  very  popular  for  local  consumption. 
Its  manufacture  is  not  different  from  the  ordinary 
type  of  cheese,  either  cheddar  or  stirred- curd,  but 
an  infusion  of  sage  leaves,  or  sage  extract  (in  which 
latter  case  the  green  color  is  secured  by  an  in- 
fusion of  fresh  leaves  of  any  inert  plant,  as  clover, 
green  corn,  etc.),  is  added  to  the  milk  before  the 
rennet  coagulation,  and  imparts  a  light  greenish 
color  and  characteristic  flavor  to  the  curd.  Ordi- 
narily, where  sage  cheese  is  made,   the  sage  is  added 


Young   America   and   Neufchatel.  203 

to  only  a  part  of  the  milk,  and  two  separate  curds 
are  manufactured  simultaneousl3%  and  mixed  together 
as  they  are  put  in  the  press,  resulting  in  cheese  of 
a   mottled   green   color. 

Young  America,  picnics,  pineapple,  and  truckle 
cheese. —  These  are  names  applied  to  various  forms 
of  small  cheeses.  The  truckle  and  Young  America 
cheeses  in  particular  are  small  cheeses  of  the  Ched- 
dar or  other  common  type,  pressed  in  sizes  of  six 
to  ten  pounds  weight.  Picnics  are  somewhat  larger 
and  are  usually  pressed  in  10 -inch  hoops  and  weigh 
from  20  to  25  pounds.  They  are  usually  soft  and 
mild -flavored.  The  pineapple  cheeses  are  pressed  in 
shapes  suggested  by  their  name,  and  are  generally 
made   as   fii'm  and   solid   as   possible. 

Neufchatel  is  a  soft  uncured  cheese,  made  by  coagu- 
lating milk  with  rennet,  allowing  the  resulting  curd 
to  become  mildly  acid  and  then  removing  the  sur- 
plus moisture  by  drainage  and  pressure,  after  which 
the  curd  is  ground,  salted,  molded  in  small  cylin- 
ders 1%  inches  in  diameter  by  2%  inches  long  and 
wrapped  first  in  thin  parchment  paper  and  then  in 
tin  foil.  Good  Neufchatel  should  be  soft,  smooth 
and  melting  in  the  mouth  without  "mushiness,"  due 
to  the  retention  of  too  much  moisture.  When  properly 
made  it  can  be  subjected  to  very  heavy  pressure  with- 
out losing  its  melting  texture.  Its  flavor  when 
fresh  is  simply  the  flavor  of  clean,  mildly  acid  coagu- 
lated milk.  The  successful  manufacture  of  Neuf- 
chatel depends  upon  securing  both  fine  texture  and 
good  flavor,  for  while,  as  a  rule,  these  two  qualities 


204  Milk   and    Its   Products. 

are  closely  connected,  it  is  quite  possible  to  have 
good  texture  with  objectionable  flavor.  It  is  prob- 
able that  the  same  conditions  of  temperature  and 
germ  growth  that  are  most  favorable  to  ripening 
cream  for  churning  are  also  most  favorable  for  the 
manufacture  of  Neufchatel  cheese.  At  any  rate,  the 
milk  should  have  some  degree  of  ripeness  before  the 
rennet  is  added.  It  is  essential  that  the  milk  be 
clean  and  pure,  that  the  acidity  is  developed  to  the 
proper  point  in  the  curd,  and  that  sufficient  pressure 
is  applied.  When  experience  in  these  last  two  points 
is  gained,  the  remainder  of  the  process  is  compara- 
tively simple,  and  in  fact,  many  of  the  details  may 
be  varied  to  a  greater  or  less  extent.  Good  clean 
milk  is  not  less  important  than  in  cheddar  cheese 
making,  as  gassy  ferments  often  make  trouble.  A 
good  pure -culture  starter,  giving  a  mild  develop- 
ment of  acid,  will  prove  of  great  assistance  in  hand- 
ling gassy  milk.  The  rennet  is  added  to  the  milk 
at  a  low  temperature  (70°  to  80°  F.)  at  the  rate  of 
1%  to  2%  ounces  per  1,000  pounds.  Too  little  ren- 
net will  give  trouble  by  making  a  curd  that  is  very 
difficult  to  drain,  and  that  tends  to  pass  through 
the  press  cloths  when  pressed.  An  excess  of  rennet 
results  in  a  curd  of  hard  texture.  It  is  better  to 
add  the  rennet  to  the  whole  mass  of  milk  in  a  vat, 
and  then  as  soon  as  the  rennet  is  thoroughly  mixed 
with  the  milk,  to  draw  it  off  into  "shot-gun"  cans 
(8  inches  in  diameter  and  20  inches  deep)  for  coagu- 
lation. The  milk  should  be  warm  enough  and  also 
ripe    enough,    so    that    coagulation    will    take    place 


Neufchatel.  205 

before  much  cream  rises  to  the  surface.  The  tem- 
perature of  the  room  may  vary  within  rather  wide 
limits,  though  if  it  is  above  80°  F.  the  curd  is  likely 
to  be  hard  and  tough,  while  if  it  is  60°  F.  or  below, 
the  curd  is  not  injured,  though  the  process  is  greatly 
retarded.  Probably  the  same  rule  holds  here  as  in 
cream -ripening,  namely,  that  it  is  not  possible  to 
name  a  single  temperature  arbitrarily  as  the  cor- 
rect one.  The  most  important  point  in  the  whole 
process  is  to  determine  w'hen  the  curd  should  be 
dumped  from  the  coagulating  cans  upon  the  drain- 
ing cloths.  It  should  stand  until  the  whey  is 
markedly  acid  to  the  taste,  as  much  so  as  mildly 
ripened  cream,  and  until  the  hand  passed  down 
between  the  sides  of  the  can  and  the  curd  notes 
that  the  latter  is  firm,  with  a  peculiar  elastic  cush- 
iony feel.  The  amount  of  whey  that  gathers  on  the 
top  of  the  curd  is  not  a  safe  indication  of  the  time 
to  dump,  for  at  high  temperatures  a  large  amount 
of  whey  often  separates  while  it  is  still  sweet,  and 
in  case  of  gassy  fermentations  the  curd  floats  and 
the  whey  is  found  at  the  bottom.  If  the  cans  are 
dumped  before  sufficient  acid  has  developed,  it  will 
be  very  difficult  to  drain  the  curds,  the  flavor  will 
be  very  bad,  the  texture  pasty  and  slimy,  and  later, 
as  the  acid  develops,  an  additional  amount  of  whey 
will  separate,  making  a  leaky  cheese.  When  ready, 
the  cans  of  coagulated  milk  should  be  dumped  on 
draining  racks  15x24  inches,  with  slatted  bottoms 
covered  with  heavy,  closely -woven  cotton  sheeting. 
The   dumping  should  be  carefully  and  skilfully  done, 


206  Milk   and   Its   Products, 

so  that  the  curd  slides  out  of  the  can  with  as  little 
breaking  as  possible.  The  conditions  are  best  when 
the  mass  of  curd,  on  being  dumped,  retains  its  form 
and  breaks  with  a  clean  vitreous  fracture.  The 
time  required  for  drainage  may  range  from  two  to 
twenty -four  hours,  varying  with  the  temperature, 
amount  of  rennet  used,  amount  of  acidity  developed, 
and  other  unknown  factors.  When  dry  enough  to 
handle  easily,  the  cloths  are  folded  up  in  such  a 
manner  as  to  enclose  the  curd,  and  the  whole  is 
pressed  under  rather  heavy  pressure  till  the  proper 
consistency  is  secured.  When  taken  from  the  press 
the  cakes  of  curd  are  brought  to  a  uniform  con- 
sistency by  kneading  or  working,  or  they  may  be 
passed  through  an  ordinary  meat  chopper.  About 
1%  per  cent  of  salt  is  then  thoroughly  incorporated 
and  the  cheese  molded  into  the  desired  shape. 
The  molding  is  a  matter  of  some  difficulty,  as  the 
particles  of  cheese  move  easily  on  themselves,  while 
they  tend  to  adhere  to  metal  or  wooden  surfaces. 
Large  factories  have  specially  constructed  machines 
for  molding  the  cheese.  On  a  small  scale,  the  most 
satisfactory  implement  is  a  smooth  tin  tube  of  the 
proper  diameter  and  long  enough  to  hold  two  or 
three  cheeses.  The  tube  is  filled  full  of  the  curd 
and  then  forced  out  of  one  end  with  a  smoothly 
fitting  piston,  after  which  the  cheeses  are  cut  apart 
with  a  thread  and  neatly  wrapped  first  in  thin  parch- 
ment paper  and  then  in  tin  foil.  According  to  the 
quality  of  milk,  from  60  to  80  standard  cheeses  should 
be  made  from  100  pounds  of  milk. 


Philadelphia   or  Square    Creams.  207 

Philadelphia  or  square  cream  cheese. — This  is  a 
soft  cheese  growing  in  popularity  in  proximity  to 
many  of  our  larger  markets.  It  resembles  the  Nenf- 
chatel,  but  is  made  of  cream  of  varying  degrees  of 
richness  and  is  put  up  in  a  different  form.  It  is 
molded  in  flat,  thin  cakes  3x4  inches,  in  a  flat  tin 
mold,  wrapped  in  parchment  paper,  and  packed  for 
shipment.  Its  manufacture  is  practically  the  same 
as  Neufchatel,  and,  in  fact,  there  is  more  or  less 
confusion  of  nomenclature  between  the  two,  as  well 
as  a  good  deal  of  variation  in  fat  content,  some 
brands  of  Neufchatel  having  a  higher  fat  content 
than   some   brands   of   square   cream,  and   vice   versa. 

Some  of  the  older  writers  describe  a  cream  cheese 
made  by  simply  draining  and  lightly  pressing  in 
square  blocks  a  thick  cream  obtained  by  setting  milk 
in  shallow  pans,  heating  over  water  till  the  cream 
"crinkles,"  and  setting  in  a  cool  place  for  twelve  to 
twenty -four  hours. 

Limlyurger. — The  Limburger  is  one  of  the  varieties 
of  cheese  whose  characteristics  are  due  to  specific 
fermentations  brought  into  the  cheese  during  the 
ripening  process.  These  fermentations  result  in  a 
well  known  putrefactive  odor  and  pungent  flavor. 
According  to  Monrad,*  the  manufacture  of  Limburger 
in  America  and  Europe  is  not  greatly  different.  Or- 
dinarily the  cheese  is  made  from  whole  milk,  but 
frequently  skimmed  or  partly  skimmed  milk  is  used. 
In  Europe  the  copper  kettle  is  commonly  employed ; 
in  America   both  the  kettle  and   the  ordinary  rectan- 

*  Cheese-making  in  Switzerland.    Winnetka,  Ul.,  1896. 


208  Mill'    and   Its    Products. 

gular  cheese  vat  are  used.  In  the  latter  case  the 
curd  is  made  in  much  the  same  v^ay  as  for  ordinary 
cheese  up  to  the  point  when  the  whey  is  drawn  off. 
The  milk  is  set  at  a  rather  high  temperature  (92°  to 
100°  ¥.).  The  curd  is  broken  into  pieces  the  size 
of  a  hen's  egg,  and  allowed  to  settle  to  the  bottom 
of  the  kettle.  It  is  then  scooped  out  and  put  in 
rectangular  molds  arranged  on  tables,  so  that  the 
whey  may  drain  off.  The  molds  are  carefully  turned 
till  the  whey  has  measurably  ceased  running,  and  the 
cheeses  will  maintain  their  form.  They  are  then 
placed  in  rows  on  a  flat  table  with  thin  pieces  of 
board  between  them,  and  subjected  to  light  pressure 
from  the  sides.  The  cheeses  are  turned  frequently  at 
first,  and  then  at  longer  intervals,  till  at  the  end  of 
thirty -six  to  forty -eight  hours  they  may  be  taken 
from  the  press.  Thej'  are  then  salted  by  rubbing 
salt  on  the  ends  and  flat  sides  for  three  or  four 
days.  After  the  first  salting  they  are  laid  on  the 
table  in  single  layers,  afterward  thej^  are  piled,  at 
first  two  deep,  then  three  or  four  deep,  so  that  the 
absorption  of  the  salt  may  be  promoted.  During 
salting  and  pressing  they  are  kept  at  a  uniform  tem- 
perature of  from  59°  to  63°  F.  They  are  then  cured 
in  a  cool  (60°  F.),  well -ventilated  cellar  nearly  satur- 
ated with  moisture,  with  careful  watching  and  much 
manipulation  and  turning.  With  the  ripening  they 
begin  to  soften.  The  curd,  at  first  hard,  takes  on 
the  characteristic  glassy,  greasy  appearance,  at  the 
same  time  that  the  rind  becomes  at  first  yellow,  then 
reddish  yellow.     The  softening  begins  on  the  outside 


Prepared    Cheese.  209 

and  proceeds  toward  the  center,  and  the  cheeses  are 
considered  to  be  marketable  when  one- quarter  of  the 
cheese   has  taken  on  its  characteristic  texture. 

Imitation  Swiss  cheese. — A  considerable  amount  of 
cheese  closelj'  resembling  the  true  Eramenthaler  is 
made  in  America.  Its  main  distinctive  characteristic 
lies  in  its  peculiar  flavor,  and  in  the  appearance  of 
the  peculiar,  so-called  Swiss  holes  in  its  texture. 
Both  of  these  are  due  to  specific  fermentations, 
which  take  place  in  the  cheese  during  the  curing 
process.      (See    Emmenthaler  cheese,   page    219.) 

These  are  the  principal  varieties  of  cheese  that 
are  manufactured  to  any  large  extent  in  America. 
There  are,  however,  a  number  of  brands  of  cheese 
upon  the  market  that,  may  properly  be  classed  under 
the    general   name    of 

Prepared  cheese. — These  fancy  brands  are  in  gen- 
eral made  from  an  ordinary  cheese  of  good  quality, 
by  removing  the  rind  and  reducing  the  remainder 
to  a  homogeneous,  more  or  less  pulpy,  mass.  To  this 
is  added  a  certain  amount  of  additional  fat,  either  in 
the  shape  of  butter  or  other  fat,  and  some  flavoring 
matter  in  the  form  of  cayenne  pepper,  brandy,  or 
something  of  like  nature.  The  cheese  is  then  packed 
closely  in  fancy  glass  or  earthenware  packages,  sealed 
tightly,  and  marketed.  The  names  under  which  it  is 
sold  vary  with  the  manufacturer  and  with  the  recipe 
under  which  it  is  made.  Many  of  them  are  sold 
under  registered  trade -marks.  Some  of  the  better 
known  are  Club  House,  Meadow  Sweet,  Canadian 
Club,   etc. 

N 


^10  Milk    and    Its    Products. 

Among  the  varieties  of  cheese  of  foreign  manu- 
facture,  the    following   are   worthy  of   mention: 

English  cheeses. — The  various  dairy  localities  in 
England  produce  cheeses  bearing  their  distinctive 
geographical  names.  In  the  main,  they  are  of  the 
cheddar  type,  and  differ  from  the  true  cheddar  only 
in  details  of  manufacture  and  in  slight  differences 
in  texture  and  flavor,  in  much  the  same  way  that 
the  American  home -trade  cheese  differs  from  the 
American  cheddar.  Of  the  English  cheeses,  the  best 
known  are  the  English  Cheddar,  Cheshire  and  Stilton; 
others  worthy  of  mention  are  Leicestershire,  Lanca- 
shire, Derbyshire,  single  and  double  Gloucester,  Wens- 
leydale    and    Wiltshire. 

Stilton. — The  manufacture  of  Stilton  cheese  is  con- 
fined almost  entirely  to  Leicestershire,  England.  Its 
manufacture  is  quite  different  from  that  of  the  com- 
mon type  of  English  and  American  cheeses,  and  in 
many  respects  more  nearly  resembles  many  of  the 
Continental  varieties,  and  is  almost  exclusively  con- 
fined to  private  dairies.  It  is  made  from  sw^eet 
milk,  and  more  commonly  separate  curds  are  made 
from  both  night's  and  morning's  milk,  the  two  being 
brought  together  when  ready  for  the  hoops.  Stilton 
cheese  is  also  made  from  a  single  curd,  and  in  this 
case  the  night's  milk  is  held  till  morning  and 
mixed  with  the  morning's  milk.  It  is  commonly  sup- 
posed that  Stilton  cheese  is  made  from  milk  which 
has  been  reinforced  with  more  or  less  cream,  but 
this  is  not  the  case  at  the  present  time ;  in  fact, 
Stilton    cheese    of    good    quality   can    be    made    from 


Stilton. 


211 


milk  not  particularly  rich  in  fat.  In  making  Stilton 
cheese  the  fresh  milk  is  put  into  a  circular  tin  vat  of 
sufficient  size  to  hold  the  milk  of  the  whole  dairy. 
The  milk   is  allowed  ^.^"\:"=^'v^^^^=^^g$^\ 

I..  N 


to  cool  to  about  85° 
F.,  and  enough  ren- 
net is  added  to  cause 
a  firm  coagulation  in 
an  hour  or  an  hour 
and  a  quarter.  While 
the  milk  is  coagu- 
lating the  strainers 
are  arranged  in 
sinks,      as     follows: 


Fig.  29.  Straining-cloths  eontaining  cnrd. 
(Redrawn  from  Jour.  Royal  Agr.  Soc, 
Srd  Series,  vol.  x.) 


The  sinks  must  be  large 
enough  to  hold  all  the  milk  that  is  made  at  one 
time.  Many  makers  prefer  earthenware,  though  on 
account  of  the  less  cost,  sinks  of  heavy  tin  are 
frequently  used.  They  are  about  six  inches  deep,  two 
to  two  and  a  half  feet  wide,  and  of  any  convenient 
length,  and  are  simply  fitted  with  outlets  and  plugs. 
For  straining  the  curds  stout  linen  cloths  are  used. 
These  are  a  yard  square  and  are  arranged  in  the 
sinks  as  shown  in  Fig.  29,  and  are  supported  by 
sticks  laid  across  the  sink  in  such  a  way  that  the 
ends  of  each  cloth  may  be  gathered  up  without  dis- 
turbing those  next  to  it.  When  the  milk  is  firmly 
coagulated,  so  that  the  curd  is  somewhat  harder 
than  for  ordinary  cheddar  cheese  making,  the  plugs 
are  put  into  the  sink  and  the  curd  dipped  into 
the  strainer  with  the  curd  ladle  or  scoop  shown  in 
Fig.   30.     This    is    done   with   a    peculiar   deft   motion 


212 


Milk    and   Its    Products. 


in  such  a  way  that  the  scoop  takes  up  a  thin  slab 
of  curd,  breaking  it  as  little  as  possible.  The  curd 
is  carefully  laid  in  the  strainer,  each  strainer  receiv- 
ing a  slice  in  turn 
until  all  the  contents 
of  the  vat  are  col- 
in   the   strainers. 


Fig.  30.     Stilton  curd   scoop. 


^^  lected 
i.:^    The  strainers  when  full 
should     contain     about 
three      to      four      gal- 
lons.     After      dipping, 

the  whey  begins  to   separate   and  is   allowed  to   stand 

until   the  curds   are   well  covered,  when  the   plugs   are 

withdrawn    and   the    whey    allowed   to    run    off.      The 

ends   of   the  strainers   are  then   gathered   up,   brought 

closely   about   the    curd,   three   corners    being   held    in 

one      hand      and      the 

whole      tightened     with 

the    fourth,     as    shown 

in  Fig.  31 ;    care  being 

taken     in     doing     this 

that    the    curd     is    not 

broken.       The    pressure 

of  the  cloth  causes  the 

whey   to  separate  more 

freely,  and  at  intervals 

of   an    hour   the    cloths 

are  tightened  about  the 

curd  until  eight  or  ten 

hours    have    passed,    when    the    curd    should    be    firm 

and    solid,    and    the    whey    entirely    separated.      The 


Fig.  31.  Method  of  tightening  strainer 
clotlis.  (Redrawn  from  Jour.  Royal 
Agr.  Soc,  3x-d  Series,  vol.  x.) 


Stilton. 


213 


cloths  are   now  removed  from   the   curd  and  the  curd 

is     cut    into    pieces    about    four    inches    square,    and 

spread    in    the    bottom    of    the    sink    and    allowed    to 

remain    till    morning    or   until    it 

has   taken    on    a    good    degree    of 

acidity,    so    that    it    is    distinctly 

sour   to    the    taste.      If   the    room 

has    been    held    at    a    temperature 

between   60°  and  65°  F.,  this   will 

occur   when    the    night's    curd    is 

36    and    the    morning's    curd    24 

hours    old.      The    two    curds    are 

then   coarsely  broken   up 

with   the    fingers,    mixed 

together,     salted     (about 

one    ounce   to  three    and 

a  half  pounds  of  curd), 

and     put     in     the     hoop 

shown   in  Fig.  32.      The 

hoops    are    made    of    tin, 


Fig.  32.    Hoop  for  Stilton  cheese. 

inches    in    diameter    and 


15  inches  high,  open  at  both  ends  and  perforated 
with  numerous  holes.  The  empty  hoop  is  set  upon 
a  thin  piece  of  board  9  inches  square,  covered  with  a 
piece  of  muslin.  The  curd  is  put  in  the  hoop 
loosely,  care  being  taken  that  the  larger  pieces  fall 
in  the  center,  and  the  smaller  ones  go  to  the  outside. 
The  hoops  when  full  are  set  aside  to  drain.  Each 
day  the  curd  is  turned  in  the  hoop,  a  fresh  board 
and  piece  of  cloth  being  used  each  time.  After  six 
to  eight  days  the  curd  next  the  hoop  begins  to  take 
on  a  fermentation,  which  gives  it  a  moist  appearance 


214  Mill'    and    Its    Products 

and  an  aromatic  odor.  The  curd  also  shrinks  slightly 
so  that  the  hoop  slips  from  it  easily.  The  cheeses 
are  theu  ready  for  the  coating  process.  The  hoops 
are  removed  entirely  and  the  cheese  taken  into 
another  room,  where  the  temperature  is  maintained 
at  from  55°  to  60°  F.,  and  the  air  is  kept  nearly 
saturated  with  moisture.  The  cheeses  are  scraped 
with  a  dull  knife,  the  cracks  being  filled  up  with 
the  material  scraped  from  the  more  prominent  places. 
After  the  scraping,  a  bandage  is  pinned  firmly  to 
the  cheese.  The  scraping  is  continued  from  day 
to  daj'  for  two  or  three  days,  clean  bandages  being 
put  on  each  time  until  the  coat  begins  to  appear. 
This  is  seen  in  the  formation  of  a  white  mold,  and 
also  in  the  appearance  of  dry  patches  upon  the  ban- 
dage. The  bandages  are  now  removed  from  the 
cheese,  and  it  remains  in  the  coating -room  for  about 
two  weeks,  being  turned  every  day,  and  resting  on 
a  board  covered  with  cloth.  When  the  coat  has 
fully  formed,  the  surface  of  the  cheese  is  a  light 
drab,  of  a  wrinkled  appearance,  and  is  then  ready 
for  the  curing -room.  The  curing -room  is  kept  at 
the  same  or  a  little  higher  temperature  than  the 
coating -room,  and  the  atmosphere  may  be  somewhat 
drier,  though  care  must  be  taken  that  it  is  not  too 
dry.  Curing  goes  on  slowly  for  two  or  three 
months,  after  which  the  cheese  may  be  removed  to 
a  cool  cellar  and  will  continue  to  improve  for  some 
time  longer.  During  the  curing  process  the  mold 
begins  to  grow  in  the  interior  of  the  cheese,  and 
when  fully  ripe  the  cheese  should   be  evenly  mottled 


Stilton.  215 

and  veined  with  blue  mold  tlirough  its  whole  sub- 
stance. A  well-made  and  well -cured  Stilton  cheese 
has    a    rough,    wrinkled,    drab    exterior.       The    cheese 


£  ig.  23  Stilton  cheese,  from  "  Stilton  Cheese  Making,"  by  J.  M.ij-shall  Dugdale, 
Jour.  Royal  Agr.  Soc,  3rd  Series,  vol.  x.,  through  the  courtesy  of  the  Sec- 
retary of  the  Royal  Agricultural  Society  of  England. 

itself  is  of  a  soft,  uniform  texture,  pale -colored,  and 
evenly  streaked  with  mold.  The  flavor  is  mild  and 
laro^ely  characteristic  of  the  mold.  The  appearance 
of   the  cheese  is  well  shown  in  the  cut,  Fig.  33. 


216  Mill'    and   Its    Products. 

Cheshire. —  Cheshire  is  a  cheese  of  the  ordinaiy 
type,  soft  ill  texture  and  rather  high  in  flavor.  It 
takes  its  name  from  the  count}'  in  England  where 
it  is  most  hirgely  made,  and  is  one  of  tlie  most 
important  of  English  cheeses.  Cheshire  cheese  is 
made  from  whole  milk,  night's  and  morning's  milk 
mixed  together  and  of  some  degree  of  ripeness.  In 
many  dairies  the  night's  milk  is  skimmed  in  the 
morning  before  the  morning's  milk  is  added  to  it, 
and  the  cream  so  obtained  reserved  to  be  added  to 
the  cream  of  the  following  day  at  the  same  time 
that  the  cream  removed  the  day  before  is  added  to 
the  milk  from  which  the  cream  is  taken.  This  is 
done  in  order  to  secure  a  certain  degree  of  ripe- 
ness. The  milk  is  set  at  about  85°  F.,  with  enough 
rennet  to  cause  a  rather  firm  coagulation  in  about 
an  hour.  It  is  then  cut  with  a  perpendicular  knife 
lengthwise  of  the  vat,  and  allowed  to  stand  ten 
minutes  or  until  a  considerable  amount  of  whey  is 
separated,  and  is  then  cut  crosswise  and  a  second 
time  lengthwise.  It  is  not  ordinarily  cut  with  the 
horizontal  knife  at  all.  After  cutting,  it  is  care- 
fully stirred  with  the  hand  for  about  an  hour,  dur- 
ing the  latter  part  of  which  time  heat  is  applied 
to  bring  the  contents  of  the  vat  back  again  to 
85°  F.  When  the  curd  is  firm  enough  so  that  a 
piece  thrown  15  to  18  inches  in  the  air  and  caught 
in  the  hand  does  not  break  it  is  allowed  to  settle, 
usually  for  about  half  an  hour,  but  before  any  acid 
develops  in  the  whey  the  curd  is  carefully  pushed 
to    one    end    of    the   vat    and    the    whey    drawn    off. 


Cheshire.  217 

The  curd  then  mats  and  is  cut  and  piled  much  as 
in  the  Cheddar  system,  except  that  the  pieces  are 
cut  smaller  and  the  cutting  is  renewed  each  time 
the  curd  is  turned,  and  the  piling  is  done  in  such 
a  way  that  the  curd  does  not  flatten  out.  The 
acidity  and  moisture  of  the  curd  is  regulated  dur- 
ing this  cutting  and  piling  process.  If  the  curd 
is  too  wet,  it  is  turned  and  piled  frequently.  If  it 
is  too  acid  and  dry  it  is  allowed  to  lie  longer  and 
not  turned  so  often.  When  some  acid  is  developed, 
so  that  the  curd  takes  on  a  glistening  appearance 
and  begins  to  grow  slightly  fibrous,  it  is  finely 
ground  in  a  peg  mill,  salted  and  put  in  the  hoops 
with  strainer  cloth  about  it  but  not  under  pressure. 
At  night  it  is  turned  and  returned  to  the  hoops. 
The  next  morning  it  is  again  turned  and  then  put 
in  the  press  with  very  slight  pressure.  Each  suc- 
ceeding day  the  turning  is  continued  and  the  pres- 
sure slightly  increased  until  it  has  been  pressed  for 
five  days  in  all.  It  is  then  taken  from  the  press 
and  allowed  to  stand  one  day  in  the  hoops  with- 
out pressure,  after  which  it  is  taken  out  and  a 
bandage  pasted  on  with  flour  paste.  It  is  allowed 
to  stand  three  days  in  the  press-room,  and  then 
put  in  the  curing -room  at  a  temperature  not  above 
65°,  and  cured  for  three  or  four  weeks.  The 
cheese  should  all  be  of  the  same  height,  and  to 
bring  this  about  hoops  of  varying  diameter  are  used 
so  that  the  variation  in  milk  from  day  to  day  will 
make  no  difference  in  the  height  of  the  cheese.  If 
a   cheese    is    too    high    after   the    first    or   second   day 


218  Milk    and    Its    Products. 

in  the  press  it  is  put  in  a  hoop  of  larger  diameter 
and  vice  versa  When  the  cheese  is  put  in  the  cur- 
ing-room, the  growth  of  a  white  mold  on  the  ends  is 
encouraged  by  laj'ing  on  the  upper  end  of  the  cheese 
a  plate  or  round  piece  of  slate.  The  cheeses  are 
kept  on  straw  in  the  curing- room,  and  when  ready 
for  market  the  ends  of  the  cheese,  except  where  the 
plate  has  lain,  are  cleaned  and  polished,  and  the 
marks  of  the  straw  show  in  the  white  mold  in  the 
center.  Cheshire  cheese  is  usually  colored.  When 
of  good  quality  it  is  of  a  soft  and  somewhat  gran- 
ular texture,  dissolving  readily  on  the  tongue,  and 
with  a  pronounced  and   rather  sharp  cheese  flavor. 

Lancashire. —  Lancashire  cheese  is  very  similar  to 
Cheshire,  though  it  is  made  somewhat  softer  and  the 
flavor  is  more  pronounced.  No  heat  is  used  to  aid 
in  the  separation  of  the  whey,  and  ordinarily,  when 
ready  for  the  press,  the  curd  is  divided  into  two 
portions,  one  of  which  is  mixed  with  the  curd 
retained  from  the  preceding  day  and  pressed,  and 
the  other  kept  to  be  mixed  with  the  curd  made  on 
the    following   day. 

Derbyshire  and  Leicestershire. —  These  cheeses  are 
made  by  modifications  of  the  Cheddar  process.  They 
are  intended  to  produce  a  somewhat  softer  cheese  to 
ripen  in  a  shorter  time.  Both  are  pressed  in  flat 
shapes,  not  over  six  inches  in  height  and  about  six- 
teen inches  in  diameter.  The  Derbyshire  is  white, 
the  Leicestershire  highly  colored.  Both  should  be 
covered  with  dark  mold  when  ready  for  the  market. 
They     bear    the     same   relation   to     English    Cheddar 


Wensleydale    and    Gorgonzola.  219 

cheese  that  the  soft  varieties  of  of  home -trade  cheese 
do  to  American  export  Cheddars. 

Wensleydale.— WQns\^jdi^\Q  cheese  is  made  in  cer- 
tain districts  in  Yorkshire,  Enghmd.  It  occupies  an 
intermediate  position  between  the  Stilton  on  the  one 
hand  and  the  ordinary  hard  cheese  on  the  other.  In 
texture  and  flavor,  and  in  the  characteristic  veins 
of  blue  mold  it  quite  closely  resembles  the  Stilton, 
but  it  is  made  after  a  process  somewhat  resembling 
the  ordinary  Derby  or  Leicestershire  or  American 
home- trade  processes,  and  is  pressed  in  a  bandage 
in  an  ordinary  press.  It  is  cured  at  a  temperature 
of  about  60°  F  ,  care  being  taken  that  the  growth  of 
the  mold  is  facilitated  even  to  the  extent  of  burrow- 
ing the  cheese  with  skewers  if  the  mold  does  not 
grow    with    suflicient   rapidity. 

Gorgonzola. —  Gorgonzola  is  an  Italian  blue-molded 
cheese  closely  resembling  Stilton  in  texture,  though 
it  is  usually  of  inferior  flavor.  Considerable  quan- 
tities of  Gorgonzola  are  imported  into  this  country, 
but  their  quality  is  not  at  all  uniform  and  the  pro- 
cess of  manufacture,  resembling  that  given  for  Stil- 
ton in  the  main,  is  not  systematically  carried  out 
by  the  peasants  in  the  north  of  Italy,  where  it  is 
made. 

Emmenthaler ,  Gruyere,  Swiss  or  Schweitzer. —  The 
cheese  made  in  the  mountains  of  Switzerland  has  a 
history  reaching  back  to  the  seventeenth  centurj-,* 
and  many  of  the  old  customs   are  still  used  ;    but,  as 

*Moiirad,  Cheese  making  in  Switzerland.    Winnetka,  111.,  1896, 


220  Milk    and    Its    Products. 

might  be  expected,  the  various  localities  have  devel- 
oped many  varieties  of  this  general  type,  in  the  same 
way  that  the  different  forms  of  cheddar  and  allied 
cheese  have  come  to  differ  from  one  another.  It  is 
generally  considered  that  the  cheese  known  as  Em- 
men  thaler  is  typical  of  the  whole  group  of  Swiss 
cheeses.  The  Emmenthaler  cheese  is  made  in  a 
large  copper  kettle  instead  of  a  vat,  and  ordinarily  the 
curd  made  in  one  vessel  is  pressed  as  a  single 
cheese.  After  the  curd  has  been  coagulated  with  ren- 
net, it  is  broken  up  in  various  ways  into  small  pieces 
as  nearly  uniform  in  size  as  possible,  and  then  heated, 
with  careful  stirring  and  attention,  up  to  135°  or 
140°  F.  After  heating,  the  curd  is  allowed  to  sink 
to  the  bottom  of  the  vessel  in  a  solid  mass,  and 
while  in  this  condition  the  bandage  is  slipped  around 
it  and  the  whole  mass  of  curd  conveyed  to  the 
hoops,  where  it  is  pressed.  In  the  subsequent  curing 
the  curd  is  usually  salted  from  the  outside  of  the 
cheese  as  it  is  curing,  and  during  the  curing  pro- 
cess certain  fermentations  go  on  which  produce  large 
holes  in  the  cheese.  These  holes  in  perfect  cheese 
should  be  uniform  in  size  and  at  equal  distances  from 
one  another.  The  casein  itself  breaks  down  into  a 
cheese  of  solid,  uniform  texture  and  characteristic  fla- 
vor. It  has  been  asserted  that  the  characteristic  fla- 
vors of  the  Swiss  cheese  are  due  to  the  character  of 
the  Alpine  pastures  upon  which  the  cows  feed,  but  it 
is  altogether  likely  that  the  curing  fermentations  have 
as  much  or  more  to  do  with  developing  these  flavors, 
Edam. — The    round    Dutch    cheeses,    colored    red, 


Edam.  221 

that  are  common  in  all  markets  take  their  name 
from  Edam,  a  small  town  in  North  Holland,  though 
the  cheeses  made  in  the  whole  of  North  Holland  are 
practically  of  this  variety.  The  cheeses  are  made 
almost  wholly  in  private  dairies,  though  there  are  a 
few  factories  in  which  the  milk  of  several  farmers  is 
pooled  together.  The  cheeses  are  made  from  partly 
skimmed  milk ;  ordinarily  the  milk  of  the  evening 
is  put  at  once  into  the  cheese  making  tub,  and  in 
the  morning  the  cream  that  has  risen  is  removed 
from  it  for  making  butter.  The  fresh  morning's 
milk  is  added  and  the  whole  set  immediately  at  a 
temperature  of  85°  F.,  with  enough  rennet  to  coagu- 
late it  in  about  40  minutes  somewhat  softer  than  for 
ordinary  cheese  making.  When  the  coagulation  is 
sufficiently  advanced  the  curd  is  broken  with  a  wire 
curd  breaker,  the  bars  of  which  are  about  three- 
fourths  of  an  inch  apart.  The  breaking  is  done  at 
first  gently  into  large  pieces  and  afterward  more 
vigorously,  a  constant  agitation  being  kept  up  by  the 
breaker  which  results  in  breaking  the  curd  into  finer 
and  finer  pieces.  After  the  whey  begins  to  separate 
a  portion  is  drawn  off  and  heated  upon  a  stove,  the 
agitation  meanwhile  of  the  curd  and  the  remaining 
whey  being  constantly  kept  up.  When  the  whey  is 
sufficiently  warm  so  that  when  added  to  the  whole 
mass  it  will  bring  the  contents  of  the  tub  up  to  85°  F., 
the  heated  whey  is  added  and  the  stirring  with  the 
breaker  kept  up  for  a  full  hour,  at  the  end  of  which 
time  the  particles  of  curd  should  be  about  the  size  of 
kernels  of  wheat,  and  firm  and  hard,  but  still  entirely 


222 


Mill-    and    Its    Products. 


sweet.  The  curd  is  then  allowed  to  settle  on  the 
bottom  of  the  tub.  When  it  is  sufficiently  matted  so 
that  it  will  hang  together  it  is  carefullj^  turned  over 
and  doubled  up  at  one  side  of  the  tub,  Avhich  is 
slightly  elevated  for  the  purpose.  The  whey  is  then 
dipped  off  and  the  curd  made  as  firm  as  possible  in 
the  tub  b}^  pressure  wdth  a  piece  of  board  and  an  iron 
weight.  When  all  the  whey  has  been  removed  that 
will   run    off  readily,  the   curd   is   broken  up   with   the 

hands    and    packed    in    the 
molds  shown  in  Fig.  34. 
It    is    made    as    firm    as 

possible    in    the    mold    by 

pressure     Avith     the     hand 


Fig.  34.     Mold  for  Edam  cheese. 


until  it  will  maintain  its 
shape.  It  is  then  removed 
from  the  mold,  neatly 
wrapped  in  cotton  cloths 
and  replaced.  The  covers 
are  put  on  and  the  molds  put  in  the  press  for  three 
hours.  When  removed  from  the  press  the  cheese 
should  be  round  or  nearly  round  in  shape.  They  are 
put  on  cup -shaped  supports  and  salted  by  thoroughly 
rubbing  the  outside  with  salt.  They  are  then  set 
aside,  covered  wdth  salt,  turned  and  rubbed  frequently 
for  three  or  four  days.  (Sometimes  the  salt  is  added 
by  immersion  in  saturated  brine.)  They  are  kept  in 
the  salt  as  long  as  any  whey  is  drawn  out  and  are 
then  put  on  shelves  in  the  curing -rooms  still  in  the 
cup -shaped  support  to  help  maintain  their  form.  The 
curing- rooms    are   kept   at  ordinary  temperatures.     In 


Edam. 


223 


many  places  they  are  the  cow  stables  that  are  vacant 
for  the  summer.  The  temperature  will  seldom  rise 
higher  than  65°  F.  After  about  three  or  four  weeks 
they  became  hard  and  firm  and  covered  with  a  white 
mold.     They  are   then  taken  down,  thoroughly  washed 


Fig.  35.     The   Market   Square,  Alkmaar,  Holland.     From   a  photograph 
by  the  author,  May  21,  1897. 

in  whey,  all  the  mold  scrubbed  off,  dried  and  greased 
with  linseed  oil,  when  they  are  ready  for  the  market. 
The  merchants  purchase  them  in  large  numbers  at  the 
weekly  markets  in  the  different  villages.  A  typical 
market  scene  is  shown  in  the  cut  (Fig..  35).  When 
taken  to  the  warehouses  they  are  colored  red,  wrapped 
in  tin  foiland  packed  for  transportation.     The  curing 


224  Milk    and   Its    Products. 

process  is  not  completed  at  the  time  the  cheese  is 
marketed.  An  Edam  cheese  at  three  or  four  weeks 
old  is  of  a  tough,  elastic  texture  and  scarce  any 
flavor.  Six  or  eight  months  or  more  are  required  to 
break  down  the  casein  and  develop  the  flavor  as  it  is 
found  in  the  perfect  Edam  cheese,  and  this  ordinarih- 
takes  place  while  the  cheeses  are  in  the  warehouse  or 
in  course  of  exportation. 

Gouda. — Gouda  cheeses  are  made  in  South  Holland 
by  a  process  very  similar  to  the  manufacture  of 
Edam.  The  whey  is  not  so  completely  separated, 
and  the  resulting  cheese  is  therefore  softer.  It  is 
pressed  in  molds  of  a  flat,  oval  shape  and  about 
ten  or  twelve  pounds  weight,  and  is  cured  faster 
than  Edam,  so  that  at  six  weeks  to  two  months 
old  it  is  a  cheese  similar  in  flavor  and  texture  to 
a  well   made    Cheddar,  although    somewhat   drier. 

Roquefort. — This  is  a  soft  or  semi-soft  cheese, 
made  in  France.  In  some  respects  it  is  the  most  fa- 
mous of  all  varieties  of  cheese.  It  is  sometimes  made 
from  goats'  as  well  as  cows'  milk,  and  it  has  peculiar 
characteristics  imparted  by  specific  fermentations  that 
are  brought  about  in  the  curing  process.  The  curing 
is  done  in  caves  in  limestone  rock,  where  the  air  is 
uniform  in  temperature,  and  in  order  to  bring  about 
the  desired  fermentations  the  germs  are  added  to  the 
curd  in  the  process  of  manufacture.  These  germs 
are  often  cultivated  upon  bread  or  similar  substance, 
and  this,  crumbled  up,  is  mingled  with  the  curd 
in  order  to  insure  the  proper  fermentation  in  the 
cheese.        Roquefort     cheese,     when     well    made    and 


Brie   and    Camembert.  225 

cured,  is  of  a  rather  soft  texture,  and  the  whole 
mass  is  permeated  with  the  molds,  imparting  a 
characteristic   flavor   to  the   cheese. 

Brie. — Another  soft  French  cheese.  The  milk  is 
put  into  small,  circular  vessels  and  the  rennet  added. 
The  curd  is  allowed  to  remain  until  it  has  become 
sufficiently  firm  to  be  removed  from  the  whey  in  one 
piece.  It  is  then  carefully  taken  up  and  put  in 
such  a  position  that  the  whey  may  drain  from  it. 
It  is  turned  frequently  and  carefully  until  sufficient 
whey  has  drained  away  so  that  the  cheeses  will 
maintain  their  form.  They  are  then  lightly  salted 
and  put  awa}^  to  cure.  During  the  curing  process 
molds  develop  on  the  outside,  but  the  fermenta- 
tions that  go  on  upon  the  inside  of  the  cheese 
result  in  the  breaking  down  of  the  casein  into  a 
creamy  mass  of  a  strong,  piquant  flavor.  The  molds 
upon  the  outside  give  to  the  cheese  a  strong  odor 
of   decomposition. 

In  very  many  cases.  Brie  cneese  is  put  upon  the 
market  in  a  very  much  more  immature  form,  so  that 
it  has  a  firm,  though  somewhat  soft  texture.  If 
allowed  to  become  fully  ripe,  though,  it  breaks  down 
into    a   semi -liquid  mass    similar   to    Camembert. 

Camembert. — Camembert  cheese  is  a  soft  cheese 
of  French  manufacture  3  to  4  inches  in  diameter 
and  X  to  %  inches  thick.  When  fully  ripe,  the 
cheese  is  coated  with  a  heavy  growth  of  red  or 
reddish  brown  mold,  and  the  interior  breaks  down 
into  a  soft,  plastic  semi-liquid  mass,  of  pungent  odor 
and  piquant  flavor.  In  the  manufacture  of  Camem- 
o 


226  Milk   and   Its   Products. 

bert  cheese  the  rennet  is  added  at  a  rather  low  tem- 
perature and  in  small  quantity,  so  that  eight  to  ten 
hours  are  required  before  the  curd  is  firm  enough 
for  the  further  treatment.  In  some  cases  a  culture 
of  the  mold  from  an  old  cheese  is  added  to  the  milk 
before  the  rennet,  in  order  to  facilitate  the  growth 
of  the  mold  during  the  ripening  process.  When  the 
milk  is  coagulated  into  rather  a  firm  curd, 
the  curd  and  whey  is  ladled  into  the  mold 
shown  in  the  cut.  Fig.  36,  which  is  placed 
upon  a  straw  mat  arranged  on  a  table  so 
that  the  whey  may  drain  off.  In 
ladling  the  curd  into  the  mold 
care  is  taken  that  each  ladleful 
is  deposited  with  as  little  break- 
age of  the  curd  as  possible,  and 
particularly  that  the 
mold,  when  full,  is 
covered  at  the  top 
with  but  a  single  slice 

of  the  curd       The  curds         ^^^'  ^^'    ^^^®  *^<^  ™<^^^  ^*^^  Camembert 

cllGGS6. 

are  allowed  to  remain 

in  the  molds  until  enough  whey  has  escaped  so  that 
the  cheeses  may  be  turned  without  breaking  the  curd. 
They  are  then  carefully  turned  and  put  upon  fresh 
mats,  at  intervals  of  twelve  hours,  when  in  the 
course  of  three  or  four  daj's  the  cheese  will  be 
sufficiently  firm  so  that  the  molds  may  be  removed. 
After  the  molds  are  removed,  turning  is  continued 
until  the  mold  begins  to  appear  on  the  surface. 
The  cheeses  are  then  put  in  a  damp  curing -room,  at  a 


D^Isigny   and   Pont   L^Eveque. 


227 


low  temperature — 55°  to  60° — for  the  remainder  of  the 
ripening  process,  which  requires  from  four  to  six  weeks. 

jyisigny. —  D'Isigny  cheese  is  similar  to  Camem- 
bert  and  Brie,  and  intermediate  in  size  between 
them  ;  in  fact,  D'Isigny  so  closely  resembles  Brie 
that  they  are  often  indistinguishable,  and,  as  a 
matter  of  fact,  D'Isigny  is  little  more  than  a  trade 
name   for   a   smaller   form    of   Brie. 

Pont  L^Eveque. — Pont  L'Eveque  is  a  soft  French 
cheese  of  rather  firmer  consistency  than  Camembert. 
The  milk  is  set  at  the  usual  temperature,  and  when 
the  curd  is  firm  enough  to  handle,  it  is  gently  cut 
into  rather  large  cubes,  which  are  carefully  placed 
upon  a  straw  mat.  As  the  whey  begins  to  separate 
and  run  off  and  the  curd  becomes  firmer,  the  ends  of 
the  mat  are  brought  together  in  such  a  w^ay  that  a 
slight  pressure  is  brought  upon  the  curd.  This  is 
continued  until  the  curd  is  firm  enough  so  that  it 
can  be  placed  in  tin  molds  like 
that  shown  in  the  cut.  Fig.  37. 
The  molds  [are  filled  and  placed 
upon  a  straw  mat.  The  molds 
are  turned  once  or  twice  a  day 
until  the  cheese  is  firm  enough 
so  that  the  mold  may  be  re- 
moved. Mold  begins  to  appear 
upon  the  cheese,  which  is  kept 
at  a  temperature  a  little  above 
60°.  When  the  cheeses  are  well 
removed  to  a  damp  room  of  a 
55°  to    58°.      When     the     curing 


Fig.  37.    Mold  for 
Pont  L'Eveque  cheese. 


molded  they  are 
temperature  from 
process     is     com- 


228 


Milk   and   Its   Products. 


plete,  the  cheeses  are  of  a  soft  consistency  similar  to 
that  of  an  unripe  Brie,  but  with  a  characteristic,  well 
ripened  flavor  fully  developed. 

Port  dii  Salut  is  one  of  the  firmest  French 
cheeses,  and  when  well  made  is  of  a  texture  similar 
to  the  best  type  of  American  home -trade  cheese, 
with  a  pleasant,  nutty  flavor.  The  milk  is  set  at 
a  rather  high  temperature  and  enough  rennet  added 
to  bring  firm  coagulation  in  thirty  minutes.  The 
curd    is    then    cut    and    heated    to    104°   and    allowed 

to  remain  in  the  whey 
until  it  takes  on  a  pe- 
culiar rubber -like  con- 
sistenc}'.  It  is  then  put 
in  the  hoop  shown  in 
the  cut,  Fig.  38,  which 
is  lined  with  a  strainer 
cloth  and  subjected  to 
slight  pressure.  When  taken  from  the  press  it  is 
slowly  ripened  at  a  low  temperature. 

Parmesan.  —  A  very  hard  Italian  cheese  made 
from  milk  with  very  little  fat,  and  from  which  a 
large  part  of  the  water  has  been  expelled.  In  curing 
it  takes  on  a  rather  sharp  flavor,  and  naturally  it 
can  be  kept  in  almost  any  climate  for  almost  any 
length  of  time.  It  is  so  hard  that  it  is  ordinarily 
grated  before  being  used,  and  is  almost  wholly 
used  to  add  piquancy  to  soups,  sauces,  and  the 
like. 


Fig.  38.    Hoop  for  Port  du  Salut  cheese. 


CHAPTER   XIII. 

BY-PBODUCTS   OF  THE  DAIRY. 

The  by-products  of  the  dairy  are  skimmed  milk, 
buttermilk  and  whey,  and  a  variety  of  products 
that  may  be  manufactured  from  them.  The  utiliza- 
tion of  these  by-products  to  the  best  advantage  is 
an  important  part  of  the  economy  of  dairy  manu- 
facture. 

Skimmed  milk,  buttermilk  and  tvliey. — By  far  the 
larger  part  of  the  dairy  by-products  must  of  neces- 
sity be  utilized  as  food  for  animals,  either  because 
of  the  cost  of  transportation  or  for  lack  of  facility 
in  marketing  many  of  the  rather  perishable  products 
that  can  be  made  from  them.  All  of  these  products 
make  a  valuable  food  for  animals,  of  course  in  pro- 
portion to  the  amount  of  the  normal  constituents  of 
the  milk  which  they  contain.  Whey  is  less  valuable 
than  skimmed  milk  or  buttermilk,  because  it  has  lost 
the  greater  part  of  its  casein  as  well  as  fat,  but 
it  still  is  of  sufficient  value  to  render  its  utilization 
of  importance.  Naturally,  we  expect  that  young  ani- 
mals (calves  and  pigs)  will  thrive  the  best  upon 
these  products,  though  skimmed  milk  has  frequently 
been  fed  to  cows  with  good  results.  All  three  are, 
however,    so   bulky  that  some  more  concentrated  food 

(229) 


230  Milk    and    Its    Products. 

should  be  fed  in  connection  with  them,  if  they  are 
used  to  the  best  advantage.  When  economically- 
fed  to  3'oung  pigs  and  calves,  skimmed  milk  and 
buttermilk  may  be  made  to  return  about  fifteen  cents 
per  hundred  weight,  and  whey  about  one- third  less. 
These  products  are  of  value  for  food  in  proportion 
as  the  milk  sugar  has  not  been  changed  to  lactic 
acid.  They  may  be  fed  in  unlimited  quantities  with- 
out ill  results  upon  the  health  of  the  animal,  ex- 
cept that  occasionally  when  the  milk  is  very  sour, 
or  when  fermentations  other  than  lactic  have  set 
in,  derangements  of  the  digestive  organs,  diarrhoea, 
etc.,  sometimes  occui\  It  is,  therefore,  advisable  that 
all  of  these  products  should  be  fed  in  as  fresh  a  con- 
dition as  possible,  and  it  has  been  found  in  many 
instances  that  the  custom  of  sterilizing  or  partially 
sterilizing  the  skimmed  milk  or  whey  at  the  factory, 
by  injecting  a  jet  of  steam  into  it  until  the  whole 
is  heated  up  to  about  180°  F.,  is  practical,  and  is  fol- 
lowed by  beneficial  results. 

Dried  casein,  paper  sizing.  —  The  casein  of  milk 
in  a  dry  form  is  useful  in  certain  manufacturing 
process,  and  has  been  found  to  be  particularly  val- 
uable for  the  preparation  of  sizing  for  paper.  The 
manufacture  of  dry  casein  for  this  purpose  has 
come  to  be  an  important  means  of  utilizing 
skimmed  milk  in  many  creameries,  and  its  prepara- 
tion is  comparatively  simple.  The  skimmed  milk  is 
collected  in  a  vat  and  the  curd  precipitated  with  a 
mineral  acid.  A  mixture  of  acetic  and  sulphuric 
acids  is  commonly  used,  and    from  %  to   1  per   cent 


Milk   Sugar.  231 

is  sufficient.  When  the  curd  has  formed,  which 
will  be  as  soon  as  the  acid  is  thoroughly  mixed 
with  the  milk,  the  whey  is  drawn  off  and  the 
curd  washed  'two  or  three  times  with  warm  water. 
It  is  then  taken  out  and  pressed  as  dry  as  possible, 
after  which  it  is  ground  rather  fine  in  a  peg  mill 
and  then  dried  in  an  oven  till  perfectly  drj^  The 
amount  usually  realized  from  the  skimmed  milk  in 
this  way  is  not  more  than  may  be  realized  when 
it    is    skilfully   fed   to    animals. 

Milk  sugar. — Milk  contains  between  4  and  5  per 
cent  of  milk  sugar,  and  the  manufacture  of  this  sugar 
has  come  to  be  an  important  industry.  In  the  manu- 
facture, whey  is  preferably  used,  or  if  skimmed  milk 
the  casein  is  first  coagulated  and  removed.  The 
water  is  then  removed  by  evaporation  until  the  crys- 
tals of  sugar  are  formed.  Various  methods  are  used 
to  rid  the  sugar  of  albumin  and  other  materials  con- 
tained in  the  whey.  Formerly  this  was  a  somewhat 
difficult  operation,  and  added  considerably  to  the  ex- 
pense of  the  manufacture,  but  recently  improvements 
have  been  made  in  this  respect,  so  that  the  cost  of 
the  manufacture  of  the  sugar  is  much  lessened.  The 
growth  of  the  industry  has  been  very  rapid,  result- 
ing in  a  much  lower  price  for  the  product  and  a  very 
much  increased  consumption.  Formerly,  almost  the 
only  use  of  milk  sugar  was  medicinal.  Now,  be- 
cause of  its  digestibility,  it  forms  an  important  in- 
gredient of  many  of  the  so-called  infants'  and  inva- 
lids' foods.  It  is  usually  prepared  in  the  form  of  a 
white  crystalline  powder,  only  mildly  sweet  to  the 
taste. 


232  3filk   and    Its    Products. 

Butch  cheese  {cottage  cheese,  schmierkase,  pot  cheese, 
etc.). — A  toothsome  and  nutritious  article  of  food  is 
made  from  sour  skimmed  milk  or  buttermilk  by  al- 
lowing the  casein  to  coagulate  by  the  'action  of  lactic 
acid  already  formed,  and  then  expelling  the  water  by 
the  aid  of  heat.  A  considerable  number  of  products 
locally  distinct,  and  differing  in  the  degree  of  dryness 
of  the  casein,  are  made  in  this  way,  the  general  pro- 
cess of  manufacture  being  to  take  sour  buttermilk,  or 
skimmed  milk  which  has  coagulated,  heating  gently  to 
from  85°  to  125°  F.,  according  to  circumstances,  drain- 
ing off  the  whey  through  a  cloth  strainer,  and  then 
reducing  the  texture  of  the  resulting  curd  by  knead- 
ing with  the  hands  or  a  pestle ;  salt  is  added,  and 
the  product  is  improved  by  the  addition  of  a  small 
amount  of  cream  or  butter,  and  occasionally  by  the 
use  of  some  of  the  more  common  spices,  as  nutmeg, 
caraway,  etc.  It  is  commonly  made  only  for  domestic 
consumption,  but  in  most  cities  and  villages,  es- 
pecially during  the  summer  months,  there  is  a  con- 
siderable demand  for  fresh  cheese  of  this  sort,  and 
its  manufacture  is  often  a  source  of  revenue  to  fac- 
tories suitably  located.  It  is  usually  sold  and  eaten 
in  a  fresh  state,  but  it  may  be  subjected  to  cer- 
tain curing  processes,  which  quite  materially  change 
its  character,  and  which  vary  widely  in  different 
localities. 

WJiey  cheese  (primost  and  myseost) . — These  are  pro- 
ducts manufactured  from  whey  in  some  of  the  north 
European  countries  and  among  the  Scandinavians  in 
our  own.     They  are  really  forms  of  evaporated  whey 


Primost,    Cheese   Food.  233 

and,  according  to  Monrad,*  are  made  somewhat  as 
follows  :  The  whey,  not  too  sour,  is  boiled  in  a 
suitable  vessel  under  a  slow  fire,  care  being  taken 
that  it  is  not  scorched  or  burnt  ;  when  the  albumi- 
nous matters  are  coagulated  they  are  removed  to  facil- 
itate evaporation,  and  the  evaporation  is  carried  on 
until  the  whole  mass  assumes  a  syrupy  condition; 
the  albuminous  matters  are  then  returned  to  the 
condensed  whej^,  the  whole  is  removed  from  the  fire 
and  mixed  rapidly  until  in  the  form  of  a  thick 
mush ;  some  cream  is  then  added  and  the  material 
pressed  in  brick  shaped  moulds,  and  after  a  day  or 
two  is  ready  for  market.  It  is  practically  unknown 
except  in  those  districts  where  the  Scandinavian 
population  is  large. 

Cheese  food.  — Within  the  last  few  years  an  en- 
terprising cheese -maker,  Mr.  J.  J.  Angus,  of  Wiscon- 
sin, has  perfected  a  system  of  manufacturing  what 
he  calls  a  complete  cheese  food.  It  is  simply  a  pro- 
duct containing  all  the  constituents  of  the  milk  in 
a  condensed  form.  An  ordinary  cheddar  cheese  is 
first  made  and  cured ;  the  whey  is  evaporated  to  a 
syrupy  consistency,  and  the  cheese  from  a  corre- 
sponding amount  of  milk  is  ground  down  to  a  pasty 
consistency  and  mixed  with  the  evaporated  whey. 
The  resulting  mass  is  pressed  into  cakes  of  conve- 
nient size,  and  under  ordinary  conditions  will  keep 
a  long  time.  The  cheese  food  is  a  soft,  homoge- 
neous substance  of  a  mildly  cheese -like,  sweetish 
flavor. 


*A  B  C  of  Cheese-making.    Winnetka,  111.  1889. 


234  Milk   and   Its   Products. 

Koumiss  is  a  beverage  made  from  milk  that  has 
undergone  alcoholic  fermentation.  It  resembles  but- 
termilk in  taste,  but  has  a  frothy  appearance  and 
the  casein  of  the  milk  is  coagulated  into  a  fine  curd. 
It  was  originally  made  from  mares'  milk  by  various 
wandering  tribes  in  Russia  and  Asia.  It  has  been 
found  to  possess  certain  dietic  properties,  and  is 
now  prepared  from  cows'  milk  by  various  formulas. 
According  to  Fleischman,  one  of  the  best  formu- 
las  is    as   follows : 

One  hundred  pounds  of  separator  skim  milk  is 
mixed  with  42  pounds  of  water,  1.75  pounds  of 
granulated  sugar,  .75  pounds  of  milk-sugar  and 
5%  to  6  ounces  of  good  yeast,  and  is  allowed  to 
stand  for  32  hours  at  a  temperature  of  100°  F. 
During  this  time  the  mixture  is  stirred  about  six 
times  at  equal  intervals.  It  is  then  decanted  into 
patent -stoppered  bottles,  the  stoppers  secured  and 
the  bottles  put  into  a  cellar  at  a  temperature  of 
55°  F.     It  should   be  used  within  six  days. 

KepMr  is  a  similar  beverage  to  Koumiss.  In  its 
preparation  the  fermentation  is  brought  about  by 
certain  bodies,  the  so-called  Kephir  grains,  of  which 
very  little  is  known.  Kephir  is  but  little  known 
in   this    country. 

Whey 71. — Quite  recently  there  has  been  patented 
in  this  country  by  Alexander  Bernstein,  of  Berlin, 
Germany,  a  nourishing,  mildly  stimulating  drink  with 
the  above  name.  It  is,  according  to  the  specifications 
of  the  letters  patent,  a  sour,  sterilized  whey,  from 
which   the  albuminous   matter  and   fat   have   been   re- 


Wheyn.  235 

moved.  It  is  put  up  without  further  treatment,  or  it 
may  be  flavored  with  hops  or  other  material,  which 
may  also  be  carbonated,  or  subjected  to  a  mild  alco- 
holic fermentation. 


CHAPTER   XIV. 
BUTTER    AND    CREESE  FACTORIES. 

Location  of  creameries. — In  the  location  of  a 
creamery  no  one  thing  is  more  important  than  to 
secure  a  well  drained  site,  and  yet  this  is  in  many 
cases  evidently  the  last  thing  thought  of.  Cream- 
eries are  located  in  any  out  of  the  way  corner  or 
bit  of  waste  land  that  happens  to  be  at  hand. 
The  drainage  is  no  less  an  important  matter  to  be 
considered  in  selecting  a  creamery  site  than  in  se- 
lecting a  house  site.  The  foundation  of  cleanliness 
in  a  creamery  begins  with  the  sewer,  and  unless 
the  waste  materials  can  be  completely  and  quickly 
drawn  away  the  labor  of  keeping  the  whole  prem- 
ises  clean   is   very   much  enhanced. 

Other  things  being  equal,  then,  elevated  ground 
should  be  selected  as  a  proper  site  for  a  creamery, 
and  if  the  advantage  of  the  elevation  can  be  made 
use  of  in  the  arrangement  of  the  working  rooms, 
so  much  the  better.  Another  matter  that  may  prove 
of  considerable  value  in  many  cases  is  a  regard  for 
the  natural  or  artificial  shelter  that  may  be  given  the 
creamery  building.  A  difference  of  six  or  eight  de- 
grees in  the  work-room  temperature  may  be  easily 
secured  by  having  a  due  regard  to  the   advantages   of 

(236) 


Arrangement   of   Creameries. 


237 


shade  from  groves  or  the  channels  of  natural  air 
drainage.  On  the  other  hand,  it  is  not  well  to  lo- 
cate the  building  on  a  too  bleak  or  exposed  site,  and 
yet  the  great  majority  of  creameries  are  either  ex- 
posed to  the 
full  rays  of 
the  August 
sun  or  to  the 
bleak  winds  of 
winter. 

Arrange- 
ment  of  build- 
in  g.  —  Two 
general  princi- 
ples govern 
the  arrange- 
ment of  cream- 
ery buildings.  In  the  one,  the  milk  is  taken  in  at  such 
an  elevation  that  it  may  flow  by  gravity  from  the 
weighing  can  to  the  receiving  vat,  thence  to  the  tem- 
pering vat,  thence  to  the  separator,  and  finally  to  the 
skimmed  milk  and  cream  vats.  In  the  other,  the  milk 
is  taken  in  on  a  level  with  the  work-room  floor,  and 
is  elevated  by  pumps.  Both  plans  have  their  advan- 
tages and  disadvantages.  The  main  advantage  of 
what  may  be  called  the  "gravity"  sj'stem  is,  that 
the  milk  flows  by  its  own  weight  during  the  whole 
course  of  manufacture,  and  no  pumps,  troublesome 
to  keep  clean,  are  necessary.  As  an  offset  to  this 
advantage,  it  entails  a  considerable  amount  of  ex- 
tra   labor    in    ascending    and    descending    the     neces- 


Fig.  39.    Diagram  of  creamery  arranged  upon  the 
"gravity"'  plan. 


238 


Milk   and   Its   Products. 


sary  stairs  or  steps.  The  pumping  system,  on 
the  other  hand,  is  economical  of  labor,  but  intro- 
duces one  or 
more  pumps, 
through  which 
the  milk  must 
be  passed,  and 
which  are  al- 
ways, even 
when  of  the 
simplest  pat- 
tern, more  or 
less  difficult  to 
keep  clean, 
and  exceeding- 
ly liable  to  be 
neglected.  In 
the  outline  diagrams  is  a  creamery  arranged  ac- 
cording to  either  system.  By  reference  to  the  gi'ound 
plan  (Fig.  41,  page  239),  it  may  be  seen  that  in 
either  case  the  amount  of  floor  space  required  is  the 
same.  In  Fig.  39  is  shown  the  elevation  under 
the  "gravity"  arrangement,  with  the  exception  that 
the  skimmed  milk  vat  is  show^n  elevated.  Here  the 
milk  is  taken  in  at  A,  passes  to  B  the  receiving 
vat,  thence  to  C  the  tempering  vat,  thence  to  D  the 
separator,  thence  to  E  the  cream  vat,  and  through 
the  pump  H  to  F  the  skimmed  milk  vat.  In  the 
pumping  system,  Fig.  40,  the  same  letters  indicate 
corresponding  parts.  It  will  be  seen  here  that  the 
inilk  is  pumped  through  G  from  B  to  C.        Referring 


Fi^.  40.       Diagram  of  creamery  arranged  upon  the 
'  pumping"  plan. 


Arrangement   of   Creameries. 


239 


again,  then,  to  the  floor  plan,  if   the    arrangement   be 
according  to  the  pumping  system,  the  operator,  stand- 


Fig.  41.  Ground  plan  of  creamery  in  Figs.  39  and  40.  A,  weighing  can  ;  B, 
receiving  vat  ;  C,  tempering  vat ;  J),  separator  ;  E,  cream  vat ;  J,  ehnrn  ; 
K,  butter  worker;  L,  cold  storage  room  ;  M,  office  ;  ^.boiler  room  ;  O,  fuel. 

ing  near  his  scales  and  receiving  vat  A,  is  but  a  step 
from  the  separator  D  and  the  boiler  N,  and  can  easily 
give  attention  to  all  parts  of  his  factory.  Whereas, 
if  the  creamery  is  arranged  upon  the  "  gravity " 
plan,  he  must  be  constantly  ascending  and  descend- 
ing a  series  of  steps  between  A  and  D.  It  would 
seem,    therefore,    that    when    the   factory   is   to    be   a 


240  Mill-    and   Its    Products. 

large  one,  requiring  the  services  of  more  than  one 
man,  that  the  "gravity"  system  is  preferable,  be- 
cause of  doing  away  with  the  objectional)le  pumps. 
Whereas,  if  the  factory  is  to  be  a  small  one,  and 
one  man  is  to  do  all  the  work,  the  amount  of 
labor  saved  by  the  more  compact  pumping  system 
will  more  than  overbalance  the  objection  arising 
from  pumps.  In  a .  factory  of  the  size  indicated, 
handling  from  three  to  five  thousand  pounds  of 
milk  per  day,  a  floor  space  of  about  18x24  feet 
will  be  required.  In  larger  factories,  it  will  be 
found  of  advantage,  in  controlling  the  temperature, 
to  introduce  partitions,  so  that  the  receiving  and 
separating  room  may  be  separated  from  the  churn- 
ing and  working  room,  and  if  much  butter  is  to 
be  made  up  into  prints,  a  third,  colder  room,  for 
printing  the  butter,  will  be  found  of  great  advan- 
tage during  the  warm  part  of  the  year.  Here,  too, 
the  question  of  labor  again  comes  into  play.  When 
the  creamery  is  so  small  that  all  the  work  is  done 
by  one  man,  labor  is  economized  by  having  all  the 
operations  conducted  in  one  room,  but  where  two  or 
three,  or  even  more  men  are  employed,  it  will  be 
found  of  advantage  to  have  separate  rooms  for  the 
different   operations. 

Construction. — The  building  should  be  laid  upon 
solid  foundation  walls  rather  than  upon  piers. 
Besides  adding  decidedly  to  the  appearance  of  the 
building,  it  aids  materially  in  keeping  the  build- 
ing warm  in  winter  and  cool  in  summer.  In  regard 
to   the   floors,  cement   floors   are    the   most    expensive 


Construction   and    Superstructure.  241 

and  the  most  durable,  and  if  well  laid  and  com- 
posed of  the  best  materials,  are  entirely  satisfactory. 
But  wooden  floors,  tightly  laid  upon  a  well -drained 
foundation,  are  fairly  durable,  and  when  out  of  re- 
pair may  be  easily  replaced  at  comparatively  small 
cost.  Whatever  the  floors,  they  must  be  thor- 
oughly sewered.  The  floor  should  slant  rapidly 
to  the  gutter,  so  that  all  water  will  quickly  run 
off  through  a  thoroughly  trapped  iron  pipe  until  the 
outside  of  the  building  is  reached,  after  which 
well -glazed  sewer  pipe  may  be  used.  An  abundant 
supply  of  pure  water  is  indispensable.  This,  under 
ordinary  conditions,  will  be  obtained  from  a  well. 
A  bored  or  driven  well  is  less  liable  to  contami- 
nation than  an  open  dug  well,  but  in  any  event 
the  site  of  the  well  should  be  chosen  with  due 
regard  to  possible  sources  of  contamination.  If 
the  water  is  very  abundant  and  at  a  temperature 
below  48°,  a  supply  of  ice  is  not  indispensable, 
except  for  cold  storage  purposes,  but  it  will  be 
found  in  most  cases  to  be  of  great  advantage. 
In  any  event,  the  means  of  readily  securing  and 
maintaining  in  the  cream  a  temperature  of  50°  F. 
or  below  is  indispensable.  Water  and  steam  pipes 
should  be  carried  to  all  parts  of  the  building  where 
their  presence  may  be  of  advantage  for  cleaning 
purposes. 

The    superstructure    may    be    as     elaborate    or    as 

simple  as   desired.      At   the   least,  it   should   offer   as 

good    protection    from     the    elements    as   a    well-built 

house     does.       In    fact,    the    construction     need     not 

p 


242 


Milk   mid   Its   Products. 


differ  from  that  of  ordinary  house  construction, 
except  that  ceiling  on  the  inside  take  the  place  of 
plaster. 

The    inside    finish     should     be     of     matched     and 
planed   lumber,   thoroughly   protected    with    hard    oil. 


F 
,  1       ' 

1       1                                                              J. 

B 

-D- 

C 

B 

E 

r 

B            ! 

I 

Fig.  42.    Plan  of  cheese  factory  properly  arranged 

It  should  be  needless  to  say  that  the  outside  should 
be  neatly  and  tastefully  painted,  yet  well -painted 
creameries  are  the  exception  and  not  the  rule. 

Cheese  factories. — All  that  was  said  in  regard  to 
the  location  of  creameries  applies  with  equal  force 
to^  cheese  factories.  Heretofore,  perhaps,  even  less 
attention  has  been  paid  to  the  drainage  of  cheese 
factories  than  to  creameries,  but  it  is  quite  as  neces- 
sary. The  arrangement  of  the  cheese  factory  is  con- 
siderably simpler  than  that  of  the  creamery,  and  mis- 


Arrangement   of  Cheese   Factories. 


243 


takes  in  arrangement  are  less  liable  to  be  made. 
The  governing  principle  should  be  that  the  milk,  in 
its  transformation  from  milk  to  cheese,  should  pass 
in  one  direction  from  the  weighing  can  toward  the 
curing     room.      The     outlines     given,    Figs.    42    and 


F 
1     i_ 

H     r 

C 

•* 

^ 

B 

B 

B 

-B- 

E 

( 

^ 

^ri_                T 

■ir- 

Fig.  43.    Plan  of  cheese  factory  improperly  arranged. 

43,  show  factories  properly  and  improperly  arranged. 
In  Fig.  42,  the  milk  taken  in  at  A  passes  into  the 
vats  at  B,  from  thence  to  the  curd  sink  C,  and  the 
press  D,  and  finally  to  the  curing  room  E,  con- 
stantly in  one  direction  and  with  a  minimum  of  hand 
labor.  Whereas,  in  Fig.  43,  following  the  same  let- 
ters, the  milk  or  curd  travels  from  one  end  of  the 
room  to  the  other  and  back  again.  While  cheese 
factories,  as  a  rule,  are  used  only  during  the  warm 
months   of    the    year,    and    perhaps    for    that    reason 


244  Milk   and   Its   Products. 

may   be    less   warmly   built,  still    it    is    not    sufficient 
that   the    superstructure   be   merely    of    siding    nailed 
to    the   joists,  leaving   the    inside    bare.       While,  per- 
haps,   it    is    not    necessary    that    the   outer  siding    be 
double,    or    that    building    paper     be    used    upon   the 
joists,  still    the   joists    should   always   be   ceiled   upon 
the    inside    and    the    ceiling    neatly    finished     in    oil. 
The    construction    of    the    curing    room  is    the    most 
important    part     of    the     cheese    factory.       Here    the 
construction    should    be     of     such    a    nature    that    a 
fairly  constant  temperature  may  be  maintained.     This 
can  hardly  be  secured  unless  the  building   is    covered 
on   the   outside  with   two   thicknesses    of   boards,  with 
paper    between    and    tightly    ceiled    upon    the    inside. 
This  part  of    the  factory,   at   least,   should   always   be 
upon   a   solid    wall    foundation.      Constructed   in   this 
way,  if   care    is   taken  to  ventilate  the  building  thor- 
oughly  at    night,    and    to    close    it    tight    during    the 
day  time,  a    fairly   cool    curing   room    can  be   secured 
even  during  the  hottest  weather  ;   but  the  temperature 
can  be  much  more  satisfactorily  regulated  if  the  ven- 
tilation  comes  through    a    sub -earth   duct   for   a    con- 
siderable  distance.     This  may  be    arranged   by  laying 
a  three  or    four -inch  glazed  sewer  pipe  at  least   four 
feet    deep,    from    a    point   on    the    surface    fifteen   or 
twenty   rods    from    the    building,    and     opening    into 
the   center    of     the    curing    room    through   the    floor. 
If   the   mouth   of  this   sub-earth   duct  can    be    placed 
in    such    a    position    that    the    prevailing    winds    will 
blow   toward    it,  a    circulation    of  cool    air  can    more 
easily  and   certainly  be  secured. 


Farm   Dairy   Buildings.  245 

Combined  butter  and  cheese  factories. — The  connec- 
tion between  the  butter  and  cheese  markets  is  such 
that  it  is  coming"  to  be  of  considerable  advantage 
for  a  factory  to  be  able  to  make  either  butter  or 
cheese.  In  many  cases  but  little  additional  room  or 
expense  is  necessary.  If  in  the  creamery  the  receiv- 
ing vat  is  of  the  same  construction  as  an  ordinary 
cheese  vat,  that  is,  piped  so  that  hot  water  or  steam 
can  be  introduced  around  it,  all  that  is  necessary  in 
order  to  make  cheese  is  to  add  a  cheese  press  and 
the  necessary  curing*  room.  In  a  cheese  factory  the 
addition  of  a  separator,  churn  and  worker  serves  to 
transform  it  into  a  creamery.  It  is  true  that  the 
presence  of  the  necessary  equipment  is  always  a 
temptation  toward  the  making  of  skimmed  milk  cheese 
during"  a  part  of  the  j^ear,  but  a  due  regard  for  the 
reputation  of  the  products  of  the  factory  will  always 
result  in  making  either  full  cream  cheese  or  butter 
alone.  Naturally  the  manufacture  of  cheese  is  most 
advantageous  during  the  summer  months,  and  the 
manufacture  of  butter  most  profitable  during  the 
winter  months.  It  is  not  at  all  unlikely  that  dairy 
manufacture  will  tend  in  this  direction  in  the  future, 
instead  of  certain  localities  being  devoted  almost  ex- 
clusively to  butter  manufacture  and  others  to  cheese 
manufacture,  as  in  the  past. 

Farm  dairy  buildings  .—Heretofore  the  farm  dairy 
work  has  shared  with  the  other  farm  industries  and 
the  domestic  life  the  room  necessary  to  its  prosecu- 
tion, and  this  has  been  and  still  is  a  main  reason 
for  the  general  inferiority  of  farm  dairy  products.     In 


246  Milk   and    Its   Products. 

order  that  the  farm  dairy  be  successful,  it  is  neces- 
sary that  some  certain  place  be  set  aside  rigorously 
for  its  prosecution.  The  dairy  cannot  be  associated 
with  the  kitchen,  the  vegetable  cellar,  or  any  other 
part  of  the  farm  buildings  except  to  its  own  detri- 
ment. The  room  or  building  devoted  to  the  farm 
dairy  need  not  be  large  nor  elaborate.  It  should 
simply  secure  a  room  of  convenient  size,  shut  off 
from  any  other  occupation,  well  lighted,  well  venti- 
lated, well  drained,  and  reasonably  cool  in  tempera- 
ture. It  is  entirely  possible  that  this  room  be  a 
part  of  the  house  cellar,  but  if  so  it  should  have 
its  own  individual  exit,  and  be  completely  shut  off 
from  the  cellar  at  large.  In  the  same  way  it  may 
be  a  part  of  any  of  the  farm  out -buildings,  or  it 
may  be  a  building  by  itself.  As  to  whether  in  a 
moderate  sized  dairy,  where  say  twenty  to  forty  cows 
are  kept,  the  dairy  should  have  a  building  separate 
from  others  or  not,  depends  largely  upon  the  way 
in  which  the  dairy  work  is  carried  on.  If  the  dairy 
is  so  large  that  power  is  required  for  the  churning, 
or  if  the  cream  is  raised  by  a  gravity  process,  it 
will  undoubtedly  be  of  advantage  that  the  dairy 
should  occupy  a  separate  building  ;  but  if  the  cream 
is  separated  by  centrifugal  process,  and  power  is  not 
required  for  churning,  then  the  milk  may  be  sepa- 
rated in  the  barn  adjoining  the  stable,  and  only  the 
cream  carried  to  the  dairy  room  proper.  There  are 
many  advantages  in  this  latter  plan.  In  the  first 
place,  the  labor  of  carrying  the  milk  to  the  dairy, 
and  the  skimmed  milk  and   buttermilk  away,  is  done 


Farm    Bairij    Buildings.  247 

away  with.  In  the  second  place,  the  room  required 
for  ripening  the  cream  and  churning  the  butter  is 
very  small,  even  for  a  dairy  of  considerable  size,  and 
may  easily  be  fitted  up  in  a  cool  corner  of  the 
cellar.  The  only  disadvantage  is  that  steam  for 
cleaning  the  utensils  is  not  conveniently  at  hand, 
but  the  advantages  in  most  cases  will  outweigh  this 
single  disadvantage.  If  this  requisite  of  the  farm 
dairy  building  or  apartment  is  secured,  namely,  a 
room  devoted  to  nothing  but  butter  or  cheese  manu- 
facture—  light,  airy  and  well  drained  —  there  is  no 
reason  why  the  very  highest  quality  of  products 
should  not  be  made  under  such  conditions,  and 
there  are  several  reasons  why  a  better  product  can 
be  made  than  under  the  ordinary  factory  conditions, 
where  the  production  and  care  of  the  milk  is  in  the 
hands  of  a  large  number  of  persons,  over  whom  the 
butter -maker  or  cheese -maker  can  at  best  exercise 
only   partial    control. 


CHAPTER   XV. 

STATISTICS  AND   ECONOMICS  OF  THE   DAIRY 
INDUSTRY. 

The  dairy  industry  in  its  development  has  fully 
kept  pace  with  other  industries  and  with  the  pop- 
ulation. The  total  number  of  milch  cows  has  in- 
creased between  two  and  three  fold  since  1850, 
though  in  1890  there  were  slightly  fewer  cows  in 
proportion  to  the  population  than  in  1850.  But  while 
the  number  of  cows  has  not  increased  faster  than  the 
population,  their  product  has  materially  done  so. 
This  is  seen  in  the  average  yield  per  cow  and  in 
the  increase  in  the  production  of  butter  and  cheese. 
In  1850  the  average  yield  per  cow  was  166%  gallons. 
This  had  increased  in  1890  to  315.4  gallons,  or 
nearly  100  per  cent.  The  total  production  of  butter 
was  nearly  four  times  as  much  in  1890  as  it  was  in 
1850,  and  the  production  of  cheese  slightly  less  than 
2%    times    as    much. 

The  various  details  of  this  development  are  well 
shown  in  the  following  tables,  compiled  from  the 
United  States  Census  reports  by  the  Dairy  Division 
of   the   United   States   Department   of    Agriculture  :* 

*U.  S.   Dept.  Agr.,  Bureau  of  Animal   Industry,  Bulletin    No.    11    (Dairy 
No.  1). 

(248) 


statistics  of  Production. 


249 


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250 


Milk   and    Its   Products. 


Value   of  principal  farm  lyroducts    of  the    United   States. 


Products. 


Meats 

Corn 

Hay 

Dairy  products   .    .. 

Wheat 

Cotton        .... 
Poultry  .    . 

Other  products  (a) 

Grand  total  .   . 


1859. 


Per 
cent 


17.9 
21.6 

9.1 
14.4 

7.5 
12. 6 


100 


Total  value. 


$300,000,000 
360,680,878 
152,671,168 
240,400,580 
124,635,545 
211, .516,625 
75,000,000 
206,639,527 


1879. 


Per 


Total  value. 


22.1 
19.2 
11.3 
10.8 
12 

5 
12.1 


$800, 
694 
409 
391 
4.36 
271 
180 
440 


000,000 
818,304 
,505,783 
,131,618 
968,463 
,6.36,121 
,000,000 
,438,3.53 


$1,671,544,323 


100 


$3,624,498,642 


Per 


Total  value. 


23.9 
1.5.9 
14 
11 
9.1 
8.2 
5  3 
12.6 


597 
526 
411 
342 
307 
200 
472 


,000.000 
,918,829 
,632,062 
,976,522 
,491,707 
008,114 
,000,000 
,492,249 


100 


$3,758,519,483 


a  "Other  products"  include  barley,  buckwheat,  flax  fiber,  flaxseed,  hemp 
hops  Irish  potatoes,  leaf  tobacco,  maple  sirup,  maple  sugar,  oats,  rice  rye' 
sorghum  molasses,   sweet  potatoes,   and  wool. 

But  it  is  not  so  much  in  the  amount  of  dairy 
product  manufactured  as  in  the  way  the  business  is 
done  that  the  dairy  industry  shows  its  most  remarka- 
ble advances.  Up  to  1850  the  whole  dairy  output 
was  produced,  manufactured,  and  marketed  from  in- 
dividual farms.  Since  then  the  introduction  and 
wonderful  growth  of  associated  dairying,  or  the  fac- 
tory system,  has  taken  place,  and  this  period  has 
also  witnessed  the  introduction  of  so  many  and  so 
varied  machines  and  utensils  that  the  dairy  practice 
of  forty  or  even  twenty  years  ago  is  entirely  rev- 
olutionized in  the  methods  of  to-day.  But  while 
associated  dairying  has  made  rapid  strides,  both  in 
butter  and  cheese  making,  it  is  only  in  cheese 
making  that  the  factory  system  can  be  said  to  have 
at  all  supplanted  private  dairying.  In  1890  only 
a  little  more  than  7  per  cent  of  all  the  cheese 
produced  was  made  outside  of  factories;    while  in  the 


Butter  and    Cheese   Factories.  251 

same  year,  of  the  1,205,508,384  pounds  of  butter 
made  in  the  country,  only  181,284,916  pounds,  or 
about    15    per  cent,  was    made    in    factories. 

Development  of  the  factory  system. — Associated 
dairying,  or  the  manufacture  of  the  milk  of  several 
patrons  at  one  place,  under  the  eye  of  a  single 
person,  was  at  first  limited  wholly  to  cheese  making. 
The  system  may  be  said  to  have  been  inaugurated 
by  Jesse  Williams,  in  Oneida  county,  N.  Y.,  when 
in  1851  he  began  the  manufacture  of  milk,  produced 
by  himself  and  several  sons  located  on  farms  near 
by,  into  cheese  under  his  immediate  supervision. 
From  this  beginning  the  number  of  cheese  factories 
increased,  slowly  at  first  but  afterward  more  rapidly, 
until  in  1870  there  were  in  operation  1,313  cheese 
factories.  Up  to  this  time  butter  factories  were  un- 
known, but  within  a  few  years  began  to  be  rapidly 
established,  and  in  1890  there  were  of  both  butter 
and  cheese  factories  4,712.  Ten  states  —  New  York, 
Wisconsin,  Iowa,  Ohio,  Pennsylvania,  Illinois,  Ver- 
mont, Minnesota,  Michigan  and  Kansas,  in  the  order 
named  —  contained  nearly  90  per  cent  of  all  the  fac- 
tories. Of  these  there  were  in  New  York  1,337, 
in  Wisconsin  966,  and  in  Iowa  500,  or  nearly  60 
per   cent   of   the    whole. 

When  the  first  butter  factories  or  creameries,  as 
they  are  more  generally  called,  were  established,  the 
milk  of  the  several  patrons  was  drawn  to  the  fac- 
tory, set  in  deep  cans,  usually  surrounded  by  running 
water,  and  afterward  skimmed  and  churned.  After 
a    time    the    gathered -cream    system  was    introduced. 


2r)2  Milk    and   Its   Products. 

Under  this  system  the  cream  was  raised  upon  the  farm, 
usually  by  a  cold  deep -setting  process,  and  the  repre- 
sentative of  the  creamery,  visiting  the  different  farms, 
skimmed  the  cream,  and  left  the  skimmed  milk  upon 
the  farm.  Later  on,  during  the  decade  beginning  in 
1880,  the  centrifugal  separator  was  introduced,  and  at 
the  present  time  by  far  the  larger  number  of  but- 
ter factories  are  operated  upon  this  system.  As  be- 
tween the  factory  system  or  the  private  daiiy  in  the 
manufacture  of  dairy  products,  both  have  their  ad- 
vantages and  disadvantages.  The  advantages  of  the 
factory  system  are  so  great  that  practically  all  of  the 
cheese  is  made  in  this  way,  the  small  amount  made 
upon  farms  and  in  private  dairies  being  almost 
wholly  made  for  domestic  or  strictly  local  consump- 
tion. These  advantages  in  the  main  are  the  saving 
of  labor  and  the  greater  uniformity  of  product.  It 
requires  no  more  time  and  but  slightly  more  labor 
to  make  six  thousand  pounds  of  milk  into  cheese 
than  six  hundred.  Few  private  dairies  produce  more 
than  the  latter  amount,  so  that  the  combination  of 
ten  men  in  a  factor^'  will  result  in  saving  the  labor 
of  at  least  five  men  in  the  manufacture  of  the  pro- 
duet.  Then  the  cost  of  building  the  proper  curing 
room  is  much  less  under  the  factory  system  than  in 
the  private  dairy.  Conditions  of  temperature  and 
moisture  can  readily  be  secured  for  a  large  amount 
of  cheese  cured  together,  that  would  practically  be  im- 
possible if  the  same  amount  of  cheese  was  distrib- 
uted in  ten  or  a  dozen  parcels  and  cured  separatelj'. 
In   associated    butter   making,  while  the  same    ad- 


Condensed   Milk.  253 

vantages  hold  true  as  in  cheese  making,  they  do  not 
manifest  themselves  to  the  same  degree.  There  is  un- 
doubtedly a  considerable  saving  of  labor  and  a  vastly 
more  uniform  product  where  the  milk  of  many  patrons 
is  manufactured  into  butter  in  a  well  equipped 
creamery  under  skilful  supervision,  but  it  is  scarcely 
possible  for  a  creamery  handling  the  milk  of  many 
cows,  scattered  over  a  wide  area  and  under  the  care 
of  many  persons,  to  make  butter  of  so  uniformly  fine 
quality  as  is  possible  where  not  only  the  milk,  from 
the  time  it  is  drawn  until  the  finished  product  is 
sent  to  market,  but  the  care  and  food  of  the  cows 
as  well,  are  under  the  same  skilful  supervision. 
One  of  the  chief  advantages  of  both  the  cheese  and 
butter  factory  system  is  that  it  removes  from  the 
farm,  and  particularly  from  the  farm  home,  a  large 
amount  of  drudgery  that  in  far  too  many  cas6s  fell 
upon  those  least  able  to  bear  it,  the  women  of  the 
household  ;  so  that  while  the  butter  of  the  very  high- 
est quality  will  probably  for  manj^  years  to  come  be 
made  in  relatively  small  individual  or  private  dairies 
upon  farms,  still  the  factory  system  is  increasing 
very  rapidly,  and  will  continue  to  do  so  until  pro- 
portionately as  much  butter  as  cheese  is  made  in 
factories. 

Condensed  milk. — In  1856  a  patent  was  granted 
to  Gail  Borden,  Jr.,  on  a  process  for  "concentrating 
sweet  milk  by  evaporation  in  vacuo,  having  no  sugar 
or  other  foreign  matter  mixed  with  it."  From  small 
beginnings  the  business  has  grown  to  enormous  pro- 
portions,   and    is    still    largely  in    the   hands   of    the 


254  Milk   and   Its   Products. 

descendants  of  the  original  patentee.  At  the  present 
time  the  condensed  product  is  made  both  with 
or  without  the  addition  of  sugar,  and  is  sold  in 
bulk  or  in  hermeticallj'  sealed  cans,  in  which  latter 
form  it  maj'  be  preserved  for  an  indefinite  time. 
By  far  the  larger  portion  of  the  product  is  made 
with   the  addition  of   sugar,  and   is    put    up    in    cans. 

According  to  Dr.  Babcock,  in  the  plain  condensed 
milk  the  water  is  reduced  to  about  59  per  cent,  the 
other  constituents  being  increased  in  proportion,  while 
the  sugared  product  contains  about  25  per  cent  of 
water   and   36    per   cent   of   cane    sugar. 

The  successful  condensation  of  milk  requires  that 
the  milk  be  produced  under  the  best  hygienic  condi- 
tions and  from  the  purest  and  most  wholesome  foods. 
Consequently  we  find  among  the  patrons  of  condens- 
ing factories  a  highly  developed  state  of  dairy  hus- 
bandry. 

Dairy  legislation. — Dairy  legislation  in  the  United 
States  has  had  two  main  objects.  First,  to  secure 
to  consumers  of  milk  an  unadulterated  product.  This 
has  resulted  in  the  establishment  in  many  states  of 
arbitrary  legal  standards  for  the  quality  of  milk,  and 
in  others  the  passage  of  general  laws  prohibiting  the 
adulteration  of  milk  in  any  way  (See  appendix  C). 
Still,  nearly  one -third  the  states  have  no  laws  what- 
ever in  regard  to  the  sale  of  milk,  though  most  of 
the  large  cities  in  these  states  have  adopted  municipal 
regulations  of  the  same  general  nature  as  the  state 
laws. 

The  second  object  of   dairy  legislation  has  been  to 


Dairy   Legislation.  255 

guarantee  the  quality  of    a   dairy  product   or   to   pre- 
vent the  sale  of  a  spurious  product  for  a  genuine  one. 
The  introduction  of   the  manufacture  of   artificial  but- 
ter or  oleomargarine  has  led  to  both  national  and  state 
regulation.       The  manufacture  of    oleomargarine,    and 
particularly  its  sale  as    genuine  butter,  caused  a  great 
injury  to   the   manufacturers  of   the   genuine   product, 
both   in   the    sale   of    their   goods   and   the   prices   re- 
ceived  for   the    same.       The  state  of    New   York   was 
one   of   the  first,  if   not  the   very  first,  to  enact  regu- 
lations controlling  the  sale   of    the    imitation    product, 
and   in    1884    passed   a   law  prohibiting   the    manufac- 
ture and  sale  of   imitation  butter  within  the    limits  of 
the    state.      This  law  was  the  subject  of   much  litiga- 
tion, but   has   been  upheld   by  the  state   and   national 
courts.      It   has  been   pretty  thoroughly  enforced,  and 
is    still   in    operation.     In  1886   the   National    Govern- 
ment  passed   a   law  imposing   an    income   tax    of   two 
cents    per   pound   upon    all    imitation   butter    made    in 
the  country,  and    levying   special    license    taxes   upon 
those  engaged  in  its  manufacture  and  sale.       This  has 
resulted   in  a  measurable  control    of   the  product,   and 
with  the  supplemental   laws  that   have  been   passed  in 
a  large  number  of   the  states  the  matter  is  now  under 
careful    and   strict   regulation.       These   laws    have  not 
resulted,  as   was   fondly  hoped   by  many  dairymen,  in 
absolutely  stopping  the  manufacture  of   imitation  but- 
ter, but   have  resulted  in  a  great  improvement   in  the 
quality  of   the  imitation  goods  and  in  securing   inno- 
cent  purchasers    against    fraud   in    palming"  off    upon 
them   a   spurious  for  a  genuine  article.      At  the  same 


256  Milk    and    Its    Products. 

time,  the  cheaper  imitation  butter  has  crowded  out  of 
the  market  the  poorer  grades  of  genuine  butter,  and 
so  improved  the  general  average  quality  of  genuine 
butter. 

More  recently  the  manufacture  of  so-called  filled 
cheese  has  been  regulated  in  the  same  way,  by  the 
passage  by  the  National  Congress,  in  1896,  of  a 
law  similar  to  the  oleomargarine  act,  placing  a  rev- 
enue tax  upon  all  filled  cheese  manufactured,  and  a 
license  tax  upon  the  manufacturers  and  dealers. 
This  filled  cheese  is  made  from  skimmed  milk,  to 
which  has  been  added  a  certain  amount  of  neutral 
animal   fat. 

Within  the  past  twenty  years  the  practice  of  mak- 
ing cheese  from  skimmed  or  partially  skimmed  milk 
has  spread  widely  throughout  the  United  States.  The 
result  has  been  that  the  reputation  of  American  cheese 
has  greatly  faHeii  in  the  market,  both  abroad  and  at 
home.  A  remedy  has  been  sought  by  the  passage  in 
several  states,  notably  New  York  and  Wisconsin,  of 
laws  authorizing  the  use,  on  cheese  made  from  whole 
milk,  of  "State  Brands"  guaranteeing  the  quality  of 
cheese  so  branded.  While  cheese -makers  were  at 
first  not  inclined  to  take  advantage  of  these  laws, 
the  "State  Brands"  are  now  extensively  used  with 
very  gratifying  results  as  to  the  reputation  of  cheese 
so  branded  in  the  general   markets. 


''Process''  Butter.  257 

trade,  large  amounts  of  poorly  made  butter  and 
butter  that  has  been  spoiled  or  partially  spoiled. 
The  butter  so  collected  is  all  melted  up  together, 
the  solid  impurities  filtered  out  and  the  fat  clarified 
by  various  processes  that  are  kept  more  or  less 
secret.  The  clarified  fat  is  then  churned  with  fresh 
skimmed  milk  and  the  resulting  butter  colored, 
salted  and  worked  in  the  usual  way.  In  some  cases 
the  better  grades  of  butter  collected  from  country 
stores  are  merely  reworked  and  uniformly  colored. 
All  such  butter,  whatever  the  treatment  it  has 
received,  is  known  as  renovated  or  process  butter, 
and  is  sold  under  the  names  "factory"  and  "imita- 
tion creamery."  It  is  very  much  improved  over  the 
original  butter  from  which  it  was  prepared,  Avhicli 
is  often  entirely  unsalable  as  butter,  but  it  is  dis- 
tinctly inferior  to  the  better  grades  of  fresh  butter 
and  injures  their  sale  to  a  greater  or  less  extent. 
For  this  reason  several  states  have  passed  laws 
requiring  that  all  butter  that  has  been  treated  as 
described  shall  be  distinctly  branded  "Renovated" 
butter. 

Dairy  markets. — In  no  one  particular  has  the  dairy 
industry  developed  in  recent  years  more  than  in  the 
line  of  production  throughout  the  year.  Formerly 
almost  the  whole  product  was  made  during  the  warm 
months.  This  is  measurably  so  still  in  the  case  of 
cheese,  but  the  demand  has  been  constantly  increas- 
ing for  fresh  butter  the  year  round,  and  at  the  pres- 
ent time  a  fairly  large  proportion  of  the  whole  output 
is   made  during   the  winter  months,   the   fresh   butter 


258  Milk   and   Its   Products. 

commanding  anywhere  from  two  to  ten  cents  per 
pound  more  than  equally  good  butter  that  has  been 
held  in  storage  for  several  months.  Very  recently, 
with  improvements  in  the  methods  of  refrigeration 
and  cold  storage,  the  price  of  stored  butter  of  the 
highest  quality  is  reaching  nearer  to  that  of  the 
fresh  made  goods,  but  the  best  consumers  still  con- 
tinue to  call  for  a  fresh  article. 


APPENDIX. 

A.     USEFUL  RULES  AND    TESTS. 

Comparison  of  Thermometer  Scales. 

Centigrade  Scale — Freezing  point  of  water  =        0 
Boiling  point  of  water     =     100 

Difference  100  degrees. 
Fahrenheit  Scale — Freezing  point  of  water  =      32 
Boiling  point  of  water     =    212 

Difference  180  degrees. 
100  degrees  C.  =  180  degrees  F. 
5        "  =      9        " 


To  Change  Degrees  Centigrade  to  Equivalent  Degrees 
Fahrenheit. 

Multiply  by  f   and   add   32  ;    e.    g. :    65°   C.    X    f  =   117  +  32 
149°  F. 


To  Change  Degrees  Fahrenheit  to  Equivalent  Degrees 
Centigrade. 

Subtract  32   and   multiply   by   f  ;    e.   g.  :    98°   F.    —  32  =  6G  X  f 
=  37°—  C. 

To  Find  the  Specific  Gravity  by  the  "  Board  of  Health  " 
Lactometer. 

Multiply  the  reading  by  .29  and  add  1.000  ;  e.  g.:  Observed  reading, 
94  X  .29  =  27.26  +  1.000  =  1.027.4-  specific  gravity. 

(259) 


260  Milk   and   Its   Products. 

To  Change  "Board  of  Health"  Lactometer  Degrees  to 
Equivalent  Quevenne  Degrees. 

Multiply  the  "Board  of  Health"  reading  by  .29;  e.  g.:  "Board 
of  Health  "  reading,  105  X  -29  =  30.45  =  30-f  Quevenne  reading. 

To  Change  Quevenne  Lactometer  Degrees  to   Equivalent 
"Board  of  Health"  Degrees. 

Divide  the  observed  Quevenne  reading  by  .29;  e.  g.;  Quevenne 
reading,  34  -=-  .29  =  117. -[-  ordinary  or  "Board  of  Health"  reading. 

Temperature  Correction  for  Lactometer. 

For  Quevenne  lactometer,  .1  lactometer  degree  for  each  degree  of 
temperature  F. 

For  ordinary  or  "Board  of  Health"  lactometer,  1  lactometer  degree 
for  each  3  degrees  of  temperature  F. 

To  be  added  if  the  temperature  is  too  high,  or  subtracted  if  it  is 
too  low. 

To  be  used  only  when  the  temperature  variation  is  less  than  10 
degrees  from  the  standard  of  the  lactometer. 

To  Estimate   Solids  Not  Fat,  and  Total  Solids,  from  the 
Specific  Gravity  and  Per  Cent  of  Fat. 

The  following  formulae  may  be  used  : 
L  +  .7   f 


Babcock  (1)  S  = 


3.8 


Babcock  (2)  S  =    ^  -f  .2  f 
4 

Richmond  (3)  T  =    ^^      -\-    ^1    +     .14 
4  5 

In  the  above  L  =  corrected  Quevenne  lactometer  reading,,  f  =  per 
cent  of  fat,  S  =  solids  not  f at ;  T  =  total  solids  ;  solids  not  fat  -(- 
fat  =  total  solids. 

To  apply  the  above  formulae,  if  the  percentage  of  fat  is  4.2  and 
the  lactometer  reading  at  60°  F.  is  32,  then 

n\    S-    L4-  -7  f       ^_    32  -f  .7  (4.2) 

.7  of  4.2  =  2.94  4-  32  =  34.94  h-  3.8  =  9.19  =  solids  not   fat. 
9.19  -f  4.2  =  13.39  =  total  solids. 


Useful   Rules   and   Tests.  261 

(2)  S  =    Jl-  +  .2  f,     S  =  -^  +  -2  (4.2) 

4  4 

32  ^  4  =  8,  .2  (4.2)  =  .84,  8  +  .84  =  8.84  =  solids  not   fat. 
8.84  4-  4.2  =  13.04  =  total  solids. 

(3)  T  =    A  +  ^  +  .14,    T  =    -^  +  liiil  +  .14 

4  5  4  5 

32  ^  4  =  8,  6  X  4.2  =  25.2  ^-  5  =  5.04. 
8  -f  5.04  +  .14  =  13.18  =  total  solids. 

Litmus  Test. 
A  method  of  determining  whether  a  liquid   is  acid  or  alkaline. 
In  acid  solutions,  blue  litmus  turns  red.* 
In  alkaline  solutions,  red  litmus  turns  blue. 

Phenolphthalein  Test. 

A  method  of  determining  whether  a  liquid  is  acid  or  alkaline. 

In  acid  solutions,  if  phenolphthalein  is  added  no  change  in  color 
is  produced. 

In  alkaline  solutions,  if  phenolphthalein  is  added  the  liquid  turns 
pink. 

To  Determine  the  Percentage  of  Lactic  Acid  in  Milk  by  the 
Use  op  Decinormal  Alkali,  or  Farrington's  Alkaline  Tablets. 

Each  c.  c.  decinormal  alkali  neutralizes  .009  grams  lactic  acid. 
Therefore,  multiply  the  number  of  c.  c.  decinormal  alkali  used  by 
.009  and  divide  the  product  by  the  number  of  grams  of  milk  taken. 
(Grams  =  c.  c.  X  1.032);  e.  g.:  20  c.  c.  of  milk  require  9  c.  c.  deci- 
normal alkali  to  neutralize  the  acid.     The  per  cent  of  acid  is  — 

.009  X  9  =  .081  grams  lactic  acid. 

.081  ^  20.64  =   .0039,  or  .39  %. 

Each  alkaline  tablet  =  3.8  c.  c.  decinormal  alkali.  Each  tablet 
is  dissolved  in  10  c.  c.  water.  Each  c.  c.  tablet  solution  =  .38 
c.  c.  decinormal  alkali.  Therefore,  each  c.  c.  tablet  solution  will 
neutralize  .009  X  .38  =  .0034  grams  lactic  acid.  Therefore,  mul- 
tiply the  number  of  c.  c.  of  tablet  solution  used  by  .0034  and 
divide  by  the  number  of  grams  of  milk  taken  (grams  =  c.  c.  X 
1.032);  e.  g.: 

20  c.  c,  of  cream  require  35  c.  c.  of  tablet  solution  to  neutralize 
the  acid.       The  per  cent  of  acid  is  — 

.0034  X  35  =  .119  grams  lactic  acid. 

■119  --  20.64  =  .0058,  or  .58%. 


262  MilJc   and   Its   Products. 

To  Determine  Lactic  Acid,  Using  17.6  c.  c.  of  Milk  or  Cream. 

Instead  of  determining  lactic  acid  as  described  above,  it  is  often 
more  convenient  to  make  the  tablet  solution  of  such  a  strength  that 
1  c.  c.  of  the  solution  will  neutralize  .01  per  cent  of  lactic  acid  in  the 
amount  of  milk  or  cream  taken.  Since  a  17.6  c.  c.  pipette  is  always 
found  where  there  is  a  Babcock  testing  outfit,  17.6  c.  c.  is  a  very 
convenient  assay,  as  it  does  not  necessitate  procuring  an  additional 
pipette.  If  5  Farrington  tablets  are  dissolved  in  97  c.  c.  of  water  the 
solution  will  be  of  such  a  strength  that  each  c.  c.  of  solution  will 
neutralize  .01  per  cent  of  lactic  acid  in  17.6  c.  c.  of  milk,  and  the  total 
number  of  c.  c.  used  will  indicate  the  amount  of  lactic  acid  present 
in  hundredths  of  one  per  cent  ;    e.  g.: 

5  tablets  are  dissolved  in  97  c.  c.  water,  and  35  c.  c.  of  the  solution 
are  required  to  neutralize  the  lactic  acid  in  17.6  c.  c.  of  cream;  the 
percentage  of  lactic  acid  present  is  therefore  .35  per  cent. 

To  Select  Milk  for  Pasteurization. 

Dissolve  any  convenient  number  of  Farrington  alkaline  tablets  in 
an  equal  number  of  ounces  of  water.  Provide  any  convenient  small 
measure,  and  to  one  measure  of  milk  add  two  measures  of  the  pre- 
pared tablet  solution.  If  the  milk  remains  uncolored,  it  contains 
more  than  .2  of  1  per  cent  of  acid,  and  is  too  sour  to  be  safely 
used.  If  it  is  colored  pink,  it  contains  less  than  .2  of  1  per  cent 
of  acid,  and  may  safely  be  used  for  pasteurizing  or  sterilizing. 
Or,  the  tablet  solution  will  be  of  very  nearly  the  same  strength, 
and  may  be  used  in  the  same  way,  if  3  tablets  are  dissolved  in  90 
c.  c.  of  water. 

To  Prepare  Viscogen  for  Restoring  the  Consistency  op 
Pasteurized  Cream. 

Two  and  one-half  parts  by  weight  of  a  good  quality  of  granulated 
sugar  are  dissolved  in  five  parts  of  water,  and  one  part  of  quick 
lime  gradually  slaked  in  three  parts  of  water.  The  resulting  milk 
of  lime  is  strained  and  added  to  the  sugar  solution.  The  mixture 
should  be  agitated  at  frequent  intervals,  and  after  two  or  three 
hours  allowed  to  settle  until  the  clear  liquid  can  be  decanted  off. 
This  clear  liquid  (viscogen)  is  the  part  used  and  should  be  kept  in 
well  -  stoppered  bottles,  as  it  loses  strength  and  becomes  dark-col- 
ored when  exposed  to  the  air.  The  darkening  in  color,  however 
does  not  impair  its  usefulness. 


Useful   Bules   and    Tests.  263 

To  Prepare  Artificial  "Starter"  or  Ferment  for  Ripening 
Milk  or  Cream. 

Sterilize  ten  pounds  of  fresh,  sweet  skimmed  or  whole  milk  at 
180°  F.  Cool  to  90°  F.,  and  add  sufficient  dry  lactic  ferment  to 
secure  coagulation  in  twenty-four  hours.  When  coagulated,  add  this 
to  the  extent  of  10  per  cent  to  enough  sterilized  whole  or  skimmed 
milk  to  make  sufficient  "starter"  for  one  day's  use.  Reserve  each 
day  enough  of  this  starter  to  prepare  the  starter  for  the  next  day, 
and  use  the  remainder  for  ripening  the  milk  or  cream,  using  for 
this  from  2  to  5  per  cent,  according  to  circumstances.  Keep  the 
starter  as  nearly  as  possible  at  a  uniform  temperature  of  80°  F.  The 
utmost  care  must  be  taken  that  no  germs  from  outside  gain  access 
to  the  starter  in  any  way  or  at  any  time.  If  this  is  not  done,  the 
starter  will  rapidly  deteriorate  or  become  foul  ;  but  with  care  in 
sterilizing  the  milk  and  utensils  it  is  not  difficult  to  propagate  a 
starter  in  this  way  continuously  for  months  without  having  it  con- 
taminated with   germs   of  undesirable  fermentations. 

To  Detect  Ordinary  Fermentations  or  "Taints"  in  Milk. 

Procure  as  many  test  tubes  one  inch  in  diameter  by  five  inches  long 
as  there  are  samples  of  milk  to  be  tested,  and  a  suitable  rack  to  hold 
them  in  an  upright  position.  Wash  and  rinse  the  tubes  thoroughly  and 
sterilize  them  by  boiling  in  water  for  thirty  minutes  or  by  exposure  to 
live  steam  in  a  sterilizing  oven  for  fifteen  minutes.  After  sterilizing 
they  may  be  allowed  to  drain  dry  and  then  should  be  kept  covered  till 
wanted.  When  wanted  for  use  the  tubes  should  be  filled  one-half  to 
two-thirds  full  with  the  suspected  milk,  closed  with  a  piece  of  glass  or 
plug  of  cotton  and  placed  in  the  rack  in  water  kept  as  nearly  constant  as 
possible  at  100°  F.  In  from  three  to  four  hours  the  samples  may  be 
inspected  without  shaking  or  stirring.  Gaseous  fermentations  will  be 
manifested  by  the  appearance  of  bubbles  of  gas  upon  the  surface  or 
throughout  the  mass,  souring  fermentations  by  coagulation  of  the  milk 
and  putrefactive  fermentations  or  "taints"  by  various  odors  manifest  to 
the  nose  when  the  covers  are  removed.  The  samples  should  be  kept 
for  at  least  twenty-four  hours  and  examinations  made  at  frequent 
intervals. 

The  Wisconsin  Curd  Test. 

This  test  is  used  for  the  same  purpose  as  the  fermentation  test 
described  above,  and  is  made  as   follows  :     Procure  as   inany  covered 


264  Milk   and   Its   Products. 

pint  glass  jars  as  there  are  samples  of  milk  to  be  tested  and  clean 
and  sterilize  them  as  described  above.  Fill  each  jar  two-thirds  full  of 
the  milk  to  be  tested,  label  them  plainly  and  put  them  up  to  the  neck 
In  a  tub  or  vat  of  water  heated  to  98°  F.  When  the  milk  has  reached 
the  temperature  of  the  water  add  ten  drops  of  rennet  extract  to  each 
jar,  and  mix  it  with  the  milk  by  shaking  the  jar.  Allow  the  jars  to 
stand  until  the  curd  is  firm  and  then  cut  the  curd  finely  with  a  case 
knife.  When  the  curd  has  settled  pour  o£f  the  whey  and  allow  the 
curd  to  settle  again  till  a  second  portion  of  whey  can  be  removed, 
The  best  tests  are  made  when  the  removal  of  whey  is  as  complete  as 
possible.  The  jars  containing  the  curd  are  then  covered  and  again 
placed  in  the  tub  and  the  temperature  maintained  as  nearly  as  pos- 
sible at  98°  F.  for  six  to  12  hours,  when  they  may  be  examined.  A 
solid,  firm  curd,  without  disagreeable  odor  or  flavor,  shows  that  the 
milk  is  pure  and  clean  and  has  been  properly  handled.  Impurities 
in  the  different  samples  are  indicated  by  the  presence  of  small 
round  holes  (gas  cells)  seen  in  the  curd  when  it  is  cut  across  with 
a  knife,  or  by  various  disagreeable  odors  that  may  be  detected  when 
the  covers  to  the  jars  are  removed.  The  apparatus  for  this  test  in 
an  improved  form  is  now  furnished  by  most  of  the  dairy  supply 
houses. 

MONRAD    ReXKET   TeST. 

This  test  is  figured  and  described  on  page  173.  It  is  used  as  fol- 
lows: To  determine  the  ripeness  of  milk  for  cheese  making,  put 
5  c.  c.  commercial  rennet  in  a  50  c.  c.  flask  and  fill  with  water  to 
the  mark.  Put  200  c.  c.  of  milk  at  86°  F.  in  a  suitable  tin  cup,  and 
allow  it  to  float  in  the  vat.  Add  5  c.  c.  of  the  diluted  rennet,  and 
note  carefully  the  time  required  for  the  first  appearance  of  coagu- 
lation. The  time  required  will  depend  upon  the  amount  of  milk 
and  rennet  used,  the  strength  of  the  rennet,  the  temperature  and 
the  ripeness  of  the  milk.  All  except  the  last  remaining  constant 
from  day  to  day,  the  degree  of  ripeness  is  measured  by  the  time 
required  for  coagulation.  The  riper  the  milk  the  shorter  the  time; 
ordinarily  from  one  and  one-half  to  two  minutes  will  be  required. 
The  diluted  rennet  must  be  made  fresh  every  day. 

Marschall  Rennet  Test. 

For  a  description  and  cut  of  this  test,  see  page  174.  Directions  for 
its  use:  To  determine  the  ripeness  of  milk  for  cheese  making,  fill 
the  vessel  to  the  o  mark  with  milk,  add  a  pipette  full  of  commercial 


Useful   Rules   and    Tests.  265 

rennet,  stir  quickly,  and  place  in  such  a  position  that  the  milk  may- 
flow  freely  from  the  orifice.  When  the  milk  ceases  to  flow,  note  the 
number  of  graduations  exposed.  The  riper  the  milk  the  less  the 
number  of  exposed  graduations. 

Hot  Iron  Test. 

A  test  used  to  indicate  the  maturity  of  curd  in  cheese  making. 
The  maturity  is  usually  coincident  with  the  amount  of  lactic  acid 
present,  so  that  the  test  is  commonly  called  the  hot  iron  test  for 
acid. 

The  test  is  made  by  heating  a  bar  of  iron  just  short  of  redness, 
or  so  that  it  will  hiss  readily.  A  mass  of  curd  is  squeezed  in  the 
hand  till  all  the  whey  possible  is  pressed  out.  The  curd  is  then 
applied  to  the  iron  ;  the  surface  of  the  curd,  melted  by  the  heat, 
sticks  to  the  iron,  and  the  remainder  is  carefully  and  gently  pulled 
away.  If  the  cui-d  is  very  immature,  the  melted  part  readily  sep- 
arates from  that  not  affected  by  the  heat,  but  when  more  mature, 
numerous  fine  threads  of  casein  are  drawn  out  when  the  two  parts 
are  separated,  the  length  of  these  threads  depending  upon  the  ma- 
turity of  the  curd,  and  commonly  measured  in  terms  of  acid,  thus, 
34-inch  acid,  2-inch  acid,  etc. 

To  Calibrate  or  Test  the  Accuracy  of  Graduation  of 
Glassware  Used  in  the  Babcock  Test. 

Observe  that  the  graduations  are  at  equal  distances  apart.  Fill 
the  bottle  carefully  to  the  o  point  with  clean  rain  water,  wipe  out 
the  neck  carefully,  and  add  from  a  pipette  or  burette  2  c.  c.  water. 
It  should  fill  the  bottle  exactly  to  the  10  point.  Or,  weigh  the 
bottle  filled  with  clean  rain  water  to  the  o  point  with  delicate  bal- 
ances, fill  to  the  10  point  and  weigh  again.  The  difference  in  weight 
should  be  2  grams.  Or,  into  a  dry,  empty  bottle  put  2  c.  c.  or 
27.18  grams  mercury,  insert  a  tight-fitting  plug  carefully  to  the  10 
point,  and  invert  the  bottle  ;  the  mercury  should  just  reach  to  the 
o  point.  The  pipette  should  hold  17.6  grams  of  water,  or  239 
grams  of  mercury.  Any  piece  showing  a  discrepancy  of  2  per  cent 
should  be  discarded. 

To  Test  Butter  or  Cheese  With  the  Babcock  Test. 

Weigh  out  on  a  balance  sensitive  to  .1  gram,  from  4  to  8  grams 
of  the  substance  to  be  tested.  Divide  into  small  pieces  and  put 
into   an  ordinary   test   bottle,    or    bottle    with    detachable    neck,    with 


266  Milk  and  lis  Products. 

about  10  c.  c.  of  warm  water.  Add  the  acid,  and  complete  the  test 
in  the  ordinary  way.  The  percentage  of  fat  will  be  found  by  the 
following  proportion  : 

Weight  of  sample   :   18   : :  observed  reading   :  per  cent  of    fat  ;   or 

18    X    observed  reading  _  ^^^,  ^^^^  ^^  ^^^. 
weight  of  sample 
€.  g. :  4.8  grams  of  cheese  tested,  showed  a  reading  of  9.2  per  cent 
fat  in  the  test  bottle.     The  cheese  contained  : 

^^  ^    ^-^  =  34.5  per  cent  fat. 
4.8  ^ 


Metric    System. 


267 


B.     METRIC   SYSTEM. 

The  meter  is  the  primary  unit  of  length.  It  is  equal  to 
Ti5T7oVoooth  part  of  the  distance  measured  on  a  meridian  of 
the  earth  from  the  equator  to  the  pole,  and  equals  about  39.37 
inches. 


Measures  of  Length. 

Equivalents. 

My  ria  meter 

10,000        meters 

6.2137    miles 

Kilometer 

1,000 

\ 

0.62137  mile,  or 
8280  ft.  10  in. 

Hectometer 

100 

328  ft.  1  in. 

Dekameter 

10 

393.7  in. 

Meter 

1         meter 

39.37  in. 

Decimeter 

.1 

3.937  in. 

Centimeter 

.01 

.3937  in. 

Millimeter 

.001      " 

.03937  in. 

Measures  of  Surface. 


Equivalents. 


Hectare 

Are 

Centare 


10,000  sq.  meters 
100  " 

1  "   meter 


2.471  acres 

119.6  sq.  yards 

1550.  sq.  inches. 


Measures  of  Capacity. 

Equivalents. 

No.  OF 
Liters. 

Cubic  Measure. 

Dry  Measure. 

Liquid  or  Wine 
Measure. 

Kiloliter,  or  Stere 

Hectoliter 

Dekaliter 

Liter 

DecUiter 

Centiliter 

Milliliter 

1000 
100 
10 
1 
.1 
.01 
.001 

1   cu.  meter 

.1"        " 
10  cu.  decimeters 
1  cu.  decimeter 

.1" 
10  cu.  centimeters 

.1  cu.  centimeter 

1.308  cu.  yards 

2  bu.  3.35  pks. 

9.08  quarts 
.909  quart 

6.1022  cu.  inches 
.6102  cu.  inch 
.061     "      " 

2&4.17  gal. 
26.417  gal. 
2.6417  gal. 
1.0567  qts. 
.&15  gill 
.338  fl.  oz. 
.27  fl.  dram 

268 


Milk   and   Its   Products. 


System  of  Weights. 

Equivalents. 

No.  OF  Geams. 

Weight  of  Water 
Maximum  Density. 

avoibdupois 
Weight. 

Millier,  or  Tonneau 

Quintal 

Myriagram 

Kilogram,  or  Kilo 

Hectogram 

Dekagram 

Gram 

Decigram 

Centigram 

Milligram 

1,000,000 
100,000 
10,000 
1,000 
100 
10 
1 
.1 
.01 
.001 

1     cu.  meter 

1     hectoliter 

1     dekaliter 

1     liter 

1     decUiter 
10     cu.  centimeters 

1     cu.  centimeter 

.1   " 
10    cu.  millimeters 

1      "    millimeter 

2204.6    pounds 
220.46       " 
22.046      " 
2.2046    ♦' 
3.5274  oz. 
.3527  '• 
15.4.32    grains 
1.5432      " 
.1548  grain 
.0154      " 

Common 
Measure. 

Equivalents. 

Common 
Measure. 

Equivalents. 

An  inch 

2.54  centimeters 

A  cu.  yard 

.7646  cu.  meter 

A  foot 

.3043  meter 

A  cord 

3.624  steres 

A  yard 

.9144      " 

A  liquid  qt. 

.9465  liter 

A  rod 

5.029  meters 

A  gallon 

3.786  liters 

A  mile 

1.6093  kilometers 

A  dry  qt. 

1.101     " 

A  sq.  inch 

6.452  sq.  centimeters 

A  peck 

8.811     " 

A  "    foot 

.0929  sq.  meter 

A  bushel 

35.24       " 

A  "    yard 

.8361   " 

An  oz.  avoirdupois 

28.35  grams 

A  "    rod 

25.29  sq.  meters 

A  pound        " 

.4536  kilogram 

An  acre 

.4047  hectare 

A  ton 

.9072  tonneau 

A  sq.  mile 

259  hectares. 

A  grain  troy 

.0648  gram 

A  cu.  inch 

16.-39  cu.  centimeters 

An  oz.      " 

31.104  grams 

A    "   foot 

.02832  cu.  meter 

A  pound  " 

.3732  kilogram 

standards  for  Milk  — Dairy  Laws.  269 

C.    LEGAL  STANDARDS  FOB  MILK—DAIBY  LAWS. 

The  following  states  and  territories  ;  viz.,  Alabama,  Arizona, 
Arkansas,  California,  Colorado,  Delaware,  Florida,  Louisiana,  Missis- 
sippi, Missouri,  Montana,  North  Dakota,  Texas  and  Wyoming,  have 
established  no  legal  standard. 

The  Dominion  of  Canada,  Connecticut,  Idaho,  Illinois,  Indiana, 
Kansas,  Kentucky,  Maryland,  Nebraska,  Nevada,  New  Mexico,  North 
Carolina,  Oklahoma,  South  Dakota,  Tennessee,  Utah,  Virginia  and 
West  Virginia  have  general  laws  prohibiting  dilution,  skimming  or 
other  adulteration. 

In  the  other  states  the  percentage  standards  are  as  follows  : 

Specific       Total 

gravity,    solids,  i.    Fats,  ^ 

District  of  Columbia., 12.5         3.5 


Georgia. 
Iowa  . . . 
Maine . . 


12  3.5 

12.5  3 

12  3 


Massachusetts  (Apr.  to  Aug.,  inclusive) 12            3 

(Sept.  to  Mar.  inchisive) 13  3.7 

Michigan 1.029-1.033  12.5         3 

Minnesota 1*^            ^-^ 

New  Hampshire 13  .... 

New  Jersey • 12  .... 

New  York 12            3 

Ohio  (May  and  June) 11-5 

"     (July  to  April,  inclusive) 12            3 

Oregon 12            3 

Pennsylvania* 1.029-1.033  12.5         3 

Rhode  Island 12            2.5 

South  Carolina 11-5         3 

Vermont  (May  and  June) 12  

(July  to  April,  inclusive) 12.5  

Washington H            3 

Wisconsin 3 

The  full  texts  of  the  national  oleomargarine  and  filled  cheese  laws 
are  as  follows  : 


♦Applies  only  to  cities  of  the  second  and  third  classes. 


270  Milk    and   Its    Products. 


THE    OLEOMARGARINE   LAW. 

AN  ACT  defining  butter,  also  imposing  a  tax  upon   and  regulating  the  manu- 
facture, sale,  importation  and  exportation  of  oleomargarine. 

Be  it  enacted  bi/  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  assembled,  That  for  the  pur- 
pose of  this  act  the  word  "butter"  shall  be  understood  to  mean 
the  food  product  usually  known  as  butter,  and  which  is  made  exclu- 
sively from  milk  or  cream,  or  both,  with  or  without  common  salt, 
and   with   or  without   additional  coloring  matter. 

Section  2.  That  for  the  purposes  of  this  act  certain  manufac- 
tured substances,  certain  extracts,  and  certain  mixtures  and  com- 
pounds, including  such  mixtures  and  compounds  with  butter,  shall 
be  known  and  designated  as  "  oleomargarine  ;  "  namely  :  All  sub- 
stances heretofore  known  as  oleomargarine,  oleo,  oleomargarine  oil, 
butterine,  lardine,  suine  and  neutral  ;  all  mixtures  and  compounds 
of  oleomargarine,  oleo,  oleomargarine-oil,  butterine,  lardine,  suine, 
and  neutral  ;  all  lard  extracts  and  tallow  extracts  ;  and  all  mix- 
tures and  compounds  of  tallow,  beef -fat,  suet,  lard,  lard-oil,  veg- 
etable-oil, aunatto  and  other  coloring  matter,  intestinal  fat,  and  offal 
fat  made  in  imitation  or  semblance  of  butter,  or  when  so  made 
calculated   or   intended   to   be   sold    as   butter,  or  for  butter. 

Sec.  3.    That   special  taxes   are   Imposed   as   follows  : 

Manufacturers  of  oleomargarine  shall  pay  six  hundred  dollars. 
Every  person  who  manufactures  oleomargarine  for  sale  shall  be 
deemed   a  manufacturer   of  oleomargarine. 

Wholesale  dealers  in  oleomargarine  shall  pay  four  hundred  and 
eighty  dollars.  Every  person  who  sells  or  offers  for  sale  oleomar- 
garine in  the  original  manufacturer's  packages  shall  be  deemed  a 
wholesale  dealer  in  oleomargarine.  But  any  manufacturer  of  oleo- 
margarine who  has  given  the  required  bond  and  paid  the  required 
special  tax,  and  who  sells  only  oleomargarine  of  his  own  produc- 
tion, at  the  place  of  manufacture,  in  the  original  packages  to  which 
the  tax-paid  stamps  are  aflftxed,  shall  not  be  required  to  pay  the 
special  tax  of  a  wholesale  dealer  in  oleomargarine  on  account  of 
such   sales. 

Retail  dealers  in  oleomargarine  shall  pay  forty-eight  dollars. 
Every  person  who  sells  oleomargarine  in  less  quantities  than  ten 
pounds  at  one  time  shall  be  regarded  as  a  retail  dealer  in  oleo- 
margarine. And  sections  thirty-two  hundred  and  thirty-two,  thirty- 
two  hundred    and    thirty-three,    thirty-two    hundred    and    thirty-four, 


Dairy   Laws.  271 

thirty-two  hundred  and  thirty-five,  thirty-two  hundred  and  thirty- 
six,  thirty-two  hundred  and  thirty-seven,  thirty-two  hundred  and 
thirty-eight,  thirty-two  hundred  and  thirty-nine,  thirty-two  hundred 
and  forty,  thirty-two  hundred  and  forty-one,  and  thirty-two  hundred 
and  forty-three  of  the  Revised  Statutes  of  the  United  States  are,  so 
far  as  applicable,  made  to  extend  to  and  include  and  apply  to  the 
special  taxes  imposed  by  this  section,  and  to  the  persons  upon 
whom    they    are   imposed. 

Sec.  4.  That  every  person  who  carries  on  the  business  of  a 
manufacturer  of  oleomargarine  without  having  paid  the  special  tax 
therefore,  as  required  by  law,  shall,  besides  being  liable  to  the 
payment  of  the  tax,  be  fined  not  less  than  one  thousand  and  not 
more  than  five  thousand  dollars  ;  and  every  person  who  carries  on 
the  business  of  a  wholesale  dealer  in  oleomargarine  without  having 
paid  the  special  tax  therefor,  as  required  by  law,  shall,  besides 
being  liable  to  the  payment  of  the  tax,  be  fined  not  less  than  five 
hundred  nor  more  than  two  thousand  dollars  ;  and  every  person 
who  carries  on  the  business  of  a  retail  dealer  in  oleomargarine 
without  having  paid  the  special  tax  therefor,  as  required  by  law, 
shall,  besides  being  liable  to  the  payment  of  the  tax,  be  fined  not 
less  than  fifty  nor  more  than  five  hundred  dollars  for  each  and 
every  offense. 

Sec.  5.  That  every  manufacturer  of  oleomargarine  shall  file  with 
the  collector  of  internal  revenue  of  the  district  in  which  his  man- 
ufactory is  located  such  notices,  inventories  and  bonds,  shall  keep 
such  books  and  render  such  returns  of  material  and  products, 
shall  put  up  such  signs  and  affix  such  number  to  his  factory, 
and  conduct  his  business  under  such  surveillance  of  officers  and 
agents,  as  the  Commissioner  of  Internal  Revenue,  with  the  appro- 
val of  the  Secretary  of  the  Treasury,  may,  by  regulation,  require. 
But  the  bond  required  of  such  manufacturer  shall  be  w^ith  sureties 
satisfactory  to  the  collector  of  internal  revenue,  and  in  a  penal 
sum  of  not  less  than  five  thousand  dollars  ;  and  the  sum  of  said 
bond  may  be  increased  from  time  to  time  and  additional  sureties  re- 
quired at  the  discretion  of  the  collector,  or  under  instructions  of 
the   Commissioner   of   Internal  Revenue. 

Sec.  6.  That  all  oleomargarine  shall  be  packed  by  the  manu-. 
facturer  thereof  in  firkins,  tubs  or  other  wooden  packages,  not  be- 
fore used  for  that  purpose,  each  containing  not  less  than  ten 
pounds,  and  marked,  stamped  and  branded  as  the  Commissioner  of 
Internal  Revenue,  with  the  approval  of  the    Secretary    of    the   Treas- 


272  Milk   and   Its    Products. 

ury,  shall  prescribe  ;  and  all  sales  made  by  manufacturers  of  oleo- 
margarine and  -wholesale  dealers  in  oleomargarine  shall  be  in 
original  stamped  packages.  Retail  dealers  in  oleomargarine  must 
sell  only  from  original  stamped  packages,  in  quantities  not 
exceeding  ten  pounds,  and  shall  pack  the  oleomargarine  sold  by 
them  in  suitable  wooden  or  paper  packages,  which  shall  be  marked 
and  branded  as  the  Commissioner  of  Internal  Revenue,  with  the 
approval  of  the  Secretary  of  the  Treasury,  shall  prescribe.  Every 
person  who  knowingly  sells  or  offers  for  sale,  or  delivers  or  offers 
to  deliver,  any  oleomargarine  in  any  other  form  than  in  new  wooden 
or  paper  packages  as  above  described,  or  who  packs  in  any  pack- 
age any  oleomargarine  in  any  manner  contrary  to  law,  or  who 
falsely  brands  any  package  or  affixes  a  stamp  on  any  package 
denoting  a  less  amount  of  tax  than  that  required  Ijy  law,  shall 
be  fined  for  each  offense  not  more  than  one  thousand  dollars  and 
be   imprisoned  not   more   than   two   years. 

Sec.  7.  That  every  manufacturer  of  oleomargarine  shall  securely 
affix,  by  pasting  on  each  package  containing  oleomargarine  manufac- 
tured by  him,  a  label  on  which  shall  be  printed,  besides  the  number 
of  the  manufactory,  and  the  district  and  state  in  wiiich  it  is  situ- 
ated, these  words  "Notice. — The  manufacturer  of  the  oleomargarine 
herein  contained  has  complied  with  all  the  requirements  of  law. 
Every  person  is  cautioned  not  to  use  either  this  package  again  or 
the  stamp  thereon  again,  nor  to  remove  the  contents  of  this  pack- 
age without  destroying  said  stamp,  under  the  penalty  provided  by 
law  in  such  cases."  Every  manufacturer  of  oleomargarine  who 
neglects  to  affix  such  label  to  any  package  containing  oleomarga- 
rine made  by  him,  or  sold  or  offered  for  sale  by  or  for  him,  and 
every  person  who  removes  any  such  label  so  affixed  from  any  such 
package,  shall  be  fined  fifty  dollars  for  each  package  in  respect  to 
which   such   offense   is  committed. 

Sec.  8.  That  upon  oleomargarine  which  shall  be  manufactured 
and  sold,  or  removed  for  consumption  or  use,  there  shall  be  assessed 
and  collected  a  tax  of  two  cents  per  pound,  to  be  paid  by  the 
manufacturer  thereof ;  and  any  fractional  part  of  a  pound  in  a 
package  shall  be  taxed  as  a  pound.  The  tax  levied  by  this  sec- 
tion shall  be  represented  by  coupon  stamps  ;  and  the  provisions  of 
existing  laws  governing  the  engraving,  issue,  sale,  accountability, 
effacement,  and  destruction  of  stamps  relating  to  tobacco  and  snuff, 
as  far  as  applicable,  are  hereby  made  to  apply  to  stamps  provided 
for  by  this    section. 


Dairy   Laws.  273 

Sec.  9.  That  whenever  any  manufacturer  of  oleomargarine  sells, 
or  removes  for  sale  or  consumption,  any  oleomargarine  upon  which 
the  tax  is  required  to  be  paid  by  stamps,  without  the  use  of  the 
proper  stamps,  it  shall  be  the  duty  of  the  Commissioner  of  Internal 
Revenue,  within  a  period  of  not  more  than  two  years  after  such 
sale  or  removal,  upon  satisfactory  proof,  to  estimate  the  amount 
of  tax  which  has  been  omitted  to  be  paid,  and  to  make  an  assess- 
ment therefor  and  certify  the  same  to  the  collector.  The  tax  so 
assessed  shall  be  in  addition  to  the  penalties  imposed  by  law  for 
such   sale   or   removal. 

Sec.  10.  That  all  oleomargarine  imported  from  foreign  countries 
shall,  in  addition  to  any  import  duty  imposed  on  the  same,  pay  an 
internal  revenue  tax  of  fifteen  cents  per  pound,  such  tax  to  be 
represented  by  coupon  stamps  as  in  the  case  of  oleomargarine 
manufactured  in  the  United  States.  The  stamps  shall  be  affixed 
and  canceled  by  the  owner  or  importer  of  the  oleomargarine  while 
it  is  in  the  custody  of  the  proper  custom-house  officers  ;  and  the 
oleomargarine  shall  not  pass  out  of  the  custody  of  said  officers 
until  the  stamps  have  been  soj  affixed  and  canceled,  but  shall  be  put 
up  in  wooden  packages,  each  containing  not  less  than  ten  pounds, 
as  prescribed  in  this  act  for  oleomargarine  manufactured  in  the 
United  States,  before  the  stamps  are  affixed  ;  and  the  owner  or 
importer  of  such  oleomargarine  shall  be  liable  to  all  the  penal 
provisions  of  this  act  prescribed  for  manufacturers  of  oleomargarine 
manufactured  in  the  United  States.  Whenever  it  is  necessary  to 
take  any  oleomargarine  so  imported  to  any  place  other  than  the 
public  stores  of  the  United  States  for  the  purpose  of  affixing  and  can- 
celing such  stamps,  the  collector  of  customs,  of  the  port  where  such 
oleomargarine  is  entered  shall  designate  a  bonded  warehouse  to  which 
it  shall  be  taken,  under  the  control  of  such  customs  officer  as  such 
collector  may  direct  ;  and  every  officer  of  customs  who  permits 
any  such  oleomargarine  to  pass  out  of  his  custody  or  control  with- 
out compliance  by  the  owner  or  importer  thereof  with  the  provi- 
sions of  this  section  relating  thereto,  shall  be  guilty  of  a  misde- 
meanor, and  shall  be  fined  not  less  than  one  thousand  dollars  nor 
more  than  five  thousand  dollars,  and  imprisoned  not  less  than  six 
months  nor  more  than  three  years.  Every  person  who  sells  or 
offers  for  sale  any  imported  oleomargarine,  or  oleomargarine  pur- 
porting or  claimed  to  have  been  imported,  not  put  up  in  pack- 
ages and  stamped  as  provided  by  this  act,  shall  be  fined  not  less 
than  five    hundred    dollars    nor    more  than    five     thousand    dollars, 

R 


274  Milk   and   Its   Products. 

and  be  imprisoned  not  less  than  six  months  nor  more  than  two 
years. 

Sec.  11.  That  every  person  who  knowingly  purchases  or  receives 
for  sale  any  oleomargarine  which  has  not  been  branded  or  stamped 
according  to  law  shall  be  liable  to  a  penalty  of  fifty  dollars  for 
each   such   offense. 

Sec.  12.  That  every  person  who  knowingly  purchases  or  receives 
for  sale  any  oleomargarine  from  any  manufacturer  who  has  not 
paid  the  special  tax  shall  be  liable  for  each  offense  to  a  penalty 
of  one  hundred  dollars,  and  to  a  forfeiture  of  all  ai-ticles  so  pur- 
chased  or  received,   or  of  the   full   value   thereof. 

Sec.  13.  That  whenever  any  stamped  package  containing  oleomar- 
garine is  emptied,  it  shall  be  the  duty  of  the  person  in  whose  hands 
the  same  is,  to  destroy  utterly  the  stamps  thereon  ;  and  any  per- 
son who  willfully  neglects  or  refuses  so  to  do  shall  for  each  such 
offense  be  fined  not  exceeding  fifty  dollars,  and  imprisoned  not  less 
than  ten  days  nor  more  than  six  months.  And  any  person  who 
fraudulently  gives  away  or  accepts  from  another,  or  who  sells,  buys, 
or  uses  for  packing  oleomargarine,  any  such  stamped  package,  shall 
for  each  such  offense  be  fined  not  exceeding  one  hundred  dollars, 
and  be  imprisoned  not  more  than  one  year.  Any  revenue  officer 
may  destroy  any  emptied  oleomargarine  package  upon  which  the  tax- 
paid   stamp   is   found. 

Sec.  14.  That  there  shall  be  in  the  office  of  the  Commissioner 
of  Internal  Revenue  an  analytical  chemist  and  a  microscopist,  who 
shall  each  be  appointed  by  the  Secretary  of  the  Treasury,  and  shall 
each  receive  a  salary  of  two  thousand  five  hundred  dollars  per  an- 
num ;  and  the  Commissioner  of  Internal  Revenue  may,  whenever  in 
his  judgment  the  necessities  of  the  service  so  require,  employ  chem- 
ists and  microscopists,  to  be  paid  such  compensation  as  he  may 
deem  proper,  not  exceeding  in  the  aggregate  any  appropriation  made 
for  that  purpose.  And  such  Commissioner  is  authorized  to  decide 
what  substances,  extracts,  mixtures  or  compounds  which  may  be  sub- 
mitted for  his  inspection  in  contested  cases  are  to  be  taxed  under 
this  act ;  and  his  decision  in  matters  of  taxation  under  this  act 
shall  be  final.  The  Commissioner  may  also  decide  whether  any 
substance  made  in  imitation  or  semblance  of  butter,  and  intended 
for  human  consumption,  contains  ingredients  deleterious  to  the  pub- 
lic health ;  but  in  case  of  doubt  or  contest  his  decisions  in  this 
class  of  cases  may  be  appealed  from  to  a  board  hereby  constituted 
for  the   purpose,  and   composed  of  the  Surgeon-General  of  the   Army, 


Dairy   Laws.  275 

the  Surgeon-General  of  the  Navy,  and  the  Secretary  of  Agricul- 
ture ;  and  the  decisions  of  this  board  shall  be  final  in  the  prem- 
ises. 

Sec.  15.  That  all  packages  of  oleomargarine  subject  to  tax  under 
this  act  that  shall  be  found  without  stamps  or  marks  as  herein  pro- 
vided, and  all  oleomargarine  intended  for  human  consumption  which 
contains  ingredients  adjudged,  as  hereinbefore  provided,  to  be  del- 
eterious to  the  public  health,  shall  be  forfeited  to  the  United  States. 
Any  person  who  shall  willfully  remove  or  deface  the  stamps,  marks, 
or  brands  on  package  containing  oleomargarine  taxed  as  provided 
herein  shall  be  guilty  of  a  misdemeanor,  and  shall  be  punished  by 
a  fine  of  not  less  than  one  hundred  dollars  nor  more  than  two  thou- 
sand dollars,  and  by  imprisonment  for  not  less  than  thirty  days  nor 
more  than   six  months. 

Sec.  16.  That  oleomargarine  may  be  removed  from  the  place  of 
manufacture  for  export  to  a  foreign  country  without  payment  of 
tax  or  aflfixing  stamps  thereto,  under  such  regulations  and  the  fil- 
ing of  such  bonds  and  other  security  as  the  Commissioner  of  In- 
ternal Revenue,  with  the  approval  of  the  Secretary  of  the  Treas- 
ury, may  prescribe.  Every  person  who  shall  export  oleomargarine 
shall  brand  upon  every  tub,  firkin,  or  other  package  containing  such 
article  the  word  "  oleomargarine,"  in  plain  Roman  letters  not  less 
than   one-half   inch    square. 

Sec.  17.  That  whenever  any  person  engaged  in  carrying  on  the 
business  of  manufacturing  oleomargarine  defrauds,  or  attempts  to 
defraud,  the  United  States  of  the  tax  on  the  oleomargarine  pro- 
duced by  him,  or  any  part  thereof,  he  shall  forfeit  the  factory  and 
manufacturing  apparatus  used  by  him,  and  all  oleomargarine  and 
all  raw  material  for  the  production  of  oleomargarine  found  in  the 
factory  and  on  the  factory  premises,  and  shall  be  fined  not  less  than 
five  hundred  dollars,  nor  more  than  five  thousand  dollars,  and  be 
imprisoned   not   less   than   six  months   nor    more  than  three  years. 

Sec.  18.  That  if  any  manufacturer  of  oleomargarine,  any  dealer 
therein,  or  any  importer  or  exporter  thereof  shall  knowingly  or 
willfully  omit,  neglect  or  refuse  to  do,  or  cause  to  be  done,  any  of 
the  things  required  by  law  in  the  carrying  on  or  conducting  of  his 
business,  or  shall  do  anything  by  this  act  prohibited,  if  there  be 
.  no  specific  penalty  or  punishment  imposed  by  any  other  section  of 
this  act  for  the  neglecting,  omitting,  or  refusing  to  do,  or  for  the 
doing  or  causing  to  be  done,  the  thing  required  or  prohibited,  he 
shall  pay   a  penalty     of  one  thousand   dollars  ;  and   if  the  person  so 


276  Milk   and   Its   Products. 

offending  be  the  manufacturer  of  or  a  wholesale  dealer  in  oleomar- 
garine, all  the  oleomargarine  owned  by  him,  or  in  which  he  has 
any   interest   as   owner,  shall   be   forfeited  to   the   United   States. 

Sec.  19.  That  all  fines,  penalties,  and  forfeitures  imposed  by 
this   act  may   be   recovered   in   any   court  of   competent    jurisdiction. 

Sec.  20.  That  the  Commissioner  of  Internal  Revenue,  with  the 
approval  of  the  Secretary  of  the  Treasury,  may  make  all  needful  reg- 
ulations  for  the   carrying   into   effect  of  this   act. 

Sec.  21.  That  this  act  shall  go  into  effect  on  the  ninetieth  day 
after  its  passage  ;  and  all  wooden  packages  containing  ten  or  more 
pounds  of  oleomargarine  found  on  the  premises  of  any  dealer  on 
or  after  the  ninetieth  day  succeeding  the  date  of  the  passage  of 
this  act  shall  be  deemed  to  be  taxable  under  section  eight  of  this 
act,  and  shall  be  taxed,  and  shall  have  affixed  thereto  the  stamps, 
marks,  and  brands  required  by  this  act  or  by  regulations  made 
pursuant  to  this  act ;  and  for  the  purposes  of  securing  the  affixing 
of  the  stamps,  marks,  and  brands  required  by  this  act,  the  oleomar- 
garine shall  be  regarded  as  having  been  manufactured  and  sold,  or 
removed  from  the  manufactory  for  consumption  or  use,  on  or  after 
tbe  day  this  act  takes  effect ;  and  such  stock  on  hand  at  the  time 
of  the  taking  effect  of  this  act  may  be  stamped,  marked,  and 
branded  under  special  regulations  of  the  Commissioner  of  Internal 
Revenue,  approved  by  the  Secretary  of  the  Treasury  ;  and  the  Com- 
missioner of  Internal  Revenue  may  authorize  the  holder  of  such 
packages  to  mark  and  brand  the  same  and  to  affix  thereto  the  pro- 
per tax-paid    stamps. 

Approved   August  2,    1886. 


THE     FILLED   CHEESE     LAW. 

AN  ACT  defining  cheese,  and    also  imposing  a  tax  upon  and    regiilating   the 
manufacture,  sale,  importation  and  exportation  of    "filled  cheese." 

Be  it  enacted  by  the  Senate  and  House  of  Representatives  of  the 
United  States  of  America  in  Congress  assembled,  That  for  the  pur- 
poses of  this  act,  the  word  "  cheese "  shall  be  understood  to  mean 
the  food  product  known  as  cheese,  and  which  is  made  from  milk 
or  cream,  and  without  the  addition  of  butter,  or  any  animal,  vege- 
table, or  other  oils  or  fats  foreign  to  such  milk  or  cream,  with  or 
without  additional  coloring  matter. 


Dairtj   Laws.  277 

Section  2,  That  for  the  purposes  of  this  act  certain  substances 
and  compounds  shall  be  known  and  designated  as  "  filled  cheese," 
namely:  All  substances  made  of  milk  or  skimmed  milk,  with  the 
admixture  of  butter,  animal  oils  or  fats,  vegetable  or  any  other  oils, 
or  compounds  foreign  to  such  milk,  and  made  in  imitation  or  sem- 
blance of   cheese. 

Sec.  3.  That  special  taxes  are  imposed  as  follows: 
Manufacturers  of  filled  cheese  shall  pay  four  hundred  dollars  for 
each  and  every  factory  per  annum.  Every  person,  firm,  or  corpora- 
tion who  manufactures  filled  cheese  for  sale  shall  be  deemed  a  man- 
ufacturer of  filled  cheese.  Wholesale  dealers  in  filled  cheese  shall  pay 
two  hundred  and  fifty  dollars  per  annum.  Every  person,  firm,  or  cor- 
poration who  sells,  or  offers  for  sale  filled  cheese  in  the  original  man- 
ufacturer's packages  for  resale,  or  to  retail  dealers  as  hereinafter  de- 
fined, shall  be  deemed  a  wholesale  dealer  in  filled  cheese.  But  any 
manufacturer  of  filled  cheese  who  has  given  the  required  bond  and 
paid  the  required  special  tax,  and  who  sells  only  filled  cheese  of  his 
own  production,  at  the  place  of  manufacture,  in  the  original  pack- 
ages, to  which  the  tax-paid  stamps  are  affixed,  shall  not  be  required 
to  pay  the  special  tax  of  a  wholesale  dealer  in  filled  cheese  on  ac- 
count  of  such    sales. 

Retail  dealers  in  filled  cheese  shall  pay  twelve  dollars  per  annum. 
Every  person  who  sells  filled  cheese  at  retail,  not  for  resale,  and 
for  actual  consumption,  shall  be  regarded  as  a  retail  dealer  in  filled 
cheese,  and  sections  thirty-two  hundred  and  thirty-two,  thirty-two 
hundred  and  thirty-three,  thirty-two  hundred  and  thirty-four,  thirty- 
two  hundred  and  thirty-five,  thirty-two  hundred  and  thirty-six,  thirty- 
two  hundred  and  thirty-seven,  thirty-two  hundred  and  thirty-eight, 
thirty-two  hundred  and  thirty-nine,  thirty-two  hundred  and  forty,  thir- 
ty-two hundred  and  forty-one,  thirty-two  hundred  and  forty-three  of 
the  Revised  Statutes  of  the  United  States  are,  so  far  as  applicable, 
made  to  extend  to  and  include  and  apply  to  the  special  taxes  im- 
posed by  this  section  and  to  the  persons,  firms,  or  corporations  upon 
whom  they  are  imposed:  Provided,  That  all  special  taxes  under  this 
act  shall  become  due  on  the  first  day  of  July  in  every  year,  or  on 
commencing  any  manufacture,  trade,  or  business  on  which  said  tax 
is  imposed.  In  the  latter  case  the  tax  shall  be  reckoned  propor- 
tionately from  the  first  day  of  the  month  in  which  the  liability  to 
the  special  tax  commences  to  the  first   day  of  July  following. 

Sec.  4  That  every  person,  firm  or  corporation  who  carries  on  the 
business  of  a  manufacturer  of  filled  cheese  without  having  paid  the 


278  Milk   and   Its   Products. 

special  tax  therefor,  as  required  by  law,  shall,  besides  being  liable 
to  ihe  pajonent  of  the  tax,  be  fined  not  less  than  four  hundred  dol- 
lars and  not  more  than  three  thousand  dollars;  and  every  person, 
firm,  or  corporation  who  carries  on  the  business  of  a  wholesale  dealer 
in  filled  cheese  without  having  paid  the  special  tax  therefor,  as  re- 
quired by  law,  shall,  besides  being  liable  to  the  payment  of  the  tax, 
be  fined  not  less  than  two  hundred  and  fifty  dollars,  nor  more  than 
one  thousand  dollars ;  and  every  person,  firm,  or  corporation,  who  car- 
ries on  the  business  of  a  retail  dealer  in  filled  cheese  without  having 
paid  the  special  tax  therefor,  as  required  by  law,  shall,  besides  being 
liable  for  the  payment  of  the  tax,  be  fined  not  less  than  forty  nor 
more  than   five  hundred   dollars   for  each   and   every  offense. 

Sec.  5.  That  every  manufactm-er  of  filled  cheese  shall  file  with 
the  collector  of  internal  revenue  of  the  district  in  which  his  man- 
ufactory is  located,  such  notices,  inventories,  and  bonds,  shall  keep 
such  books  and  render  such  returns  of  materials  and  products,  shall 
put  up  such  signs  and  afi&x  such  number  to  his  factory,  and  con- 
duct his  business  under  such  surveillance  of  oflficers  and  agents  as 
the  Commissioner  of  Internal  Revenue,  with  the  approval  of  the 
Secretary  of  the  Treasury,  may  by  regulation  require.  But  the  bond 
required  of  such  manufacturer  shall  be  with  sureties  satisfactory  to 
the  collector  of  internal  revenue,  and  in  a  penal  sum  of  not  less  than 
five  thousand  dollars;  and  the  amount  of  said  bond  may  be  in- 
creased from  time  to  time,  and  additional  sureties  required,  at  the 
discretion  of  the  collector  or  under  instructions  of  the  Commissioner 
of  Internal  Revenue.  Any  manufacturer  of  filled  cheese  who  fails 
to  comply  with  the  provisions  of  this  section,  or  with  the  regula- 
tions herein  authorized,  shall  be  deemed  guilty  of  a  misdemeanor, 
and  upon  conviction  thereof  shall  be  fined  not  less  than  five  hun- 
dred nor  more  than   one   thousand   dollars. 

Sec.  6.  That  filled  cheese  shall  be  packed  by  the  manufacturers 
in  wooden  packages  only,  not  before  used  for  that  purpose,  and 
marked,  stamped,  and  branded  with  the  words  "  filled  cheese,"  in 
black-faced  letters  not  less  than  two  inches  in  length,  in  a  circle 
in  the  center  of  the  top  and  bottom  of  the  cheese;  and  in  black- 
faced  letters  of  not  less  than  two  inches  in  length  in  line  from 
the  top  to  the  bottom  of  the  cheese,  on  the  side  in  four  places 
equidistant  from  each  other  ;  and  the  package  containing  such  cheese 
shall  be  marked  in  the  same  manner,  and  in  the  same  number  of 
places,  and  in  the  same  desci*iption  of  letters  as  above  provided  for 
the  marking  of  the   cheese;    and   all   sales  or  consignments  made  by 


Dairy    Laws.  279 

manufacturer?  of  filled  cheese  to  wholesale  dealers  in  filled  cheese 
or  to  exporters  of  filled  cheese  shall  be  in  original  stamped  pack- 
ages. Retail  dealers  in  filled  cheese  shall  sell  only  from  original 
stamped  packages,  and  shall  pack  the  filled  cheese,  when  sold,  in 
suitable  wooden  or  paper  packages  which  shall  be  marked  and  branded 
in  accordance  with  the  rules  and  regulations  to  be  prescribed  by  the 
Commissioner  of  Internal  Revenue,  with  the  approval  of  the  Secre- 
tary of  the  Treasury.  Every  person  who  knowingly  sells  or  otfers 
to  sell,  or  delivers  or  offers  to  deliver,  filled  cheese  in  any  other 
form  than  in  new  wooden  or  paper  packages,  marked  and  branded 
as  hereinbefore  provided  and  as  above  described,  or  who  packs  in  any 
package  or  packages  filled  cheese  in  any  manner  contrary  to  law, 
or  who  falsely  brands  any  package  or  affixes  a  stamp  on  any  pack- 
age denoting  a  less  amount  of  tax  than  that  required  by  law,  shall 
upon  conviction  thereof  be  fined  for  each  and  every  offense  not 
less  than  fifty  dollars  and  not  more  than  five  hundred  dollars, 
or  be  imprisoned  not  less  than  thirty  days  nor  moi-e  than  one 
year. 

Sec.  7.  That  all  retail  and  wholesale  dealers  in  filled  cheese 
shall  display  in  a  conspicuous  place  in  his  or  their  salesroom  a  sign 
bearing  the  words,  "  Filled  cheese  sold  here  "  in  black-faced  letters  not 
less  than  six  inches  in  length,  upon  a  white  ground,  with  the  name 
and  number  of  the  revenue  district  in  which  his  or  their  business 
is  conducted;  and  any  wholesale  or  retail  dealer  in  filled  cheese 
who  fails  or  neglects  to  comply  with  the  provisions  of  this  section 
shall  be  deemed  guilty  of  a  misdemeanor,  and  shall  on  conviction 
thereof  be  fined  for  each  and  every  offense  not  less  than  fifty  dol- 
lars  and  not  more  than  two   hundi-ed   dollars. 

Sec.  8.  That  every  manufacturer  of  filled  cheese  shall  securely 
affix,  by  pasting  on  each  package  containing  filled  cheese  manufac- 
tured by  him,  a  label  on  which  shall  be  printed,  besides  the  num- 
ber of  the  manufactory  and  the  district  and  state  in  which  it  is 
situated,  these  words:  "  Notice. — The  manufacturer  of  the  filled  cheese 
herein  contained  has  complied  with  all  the  requirements  of  the 
law.  Every  person  is  cautioned  not  to  use  either  this  package 
again  or  the  stamp  thereon  again,  nor  to  remove  the  contents  of 
this  package  without  destroying  said  stamp,  under  the  penalty  pro- 
vided by  law  in  such  cases."  Every  manufacturer  of  filled  cheese 
who  neglects  to  affix  such  label  to  any  package  containing  filled 
cheese  made  by  him  or  sold  or  offered  for  sale  by  or  for  him, 
and  every  person  who  removes    any   such  label  so   affixed  from    any 


280  Milk   and   Its   Products. 

such  package,  shall  be  fined  fifty  dollars  for  each  package  in  re- 
spect  to   -which   such   offense   is   committed. 

Sec.  9.  That  upon  all  filled  cheese  which  shall  be  manufactured 
there  shall  be  assessed  and  collected  a  tax  of  one  cent  per  pound, 
to  be  paid  by  the  manufacturer  thereof;  and  any  fractional  part  of 
a  pound  in  a  package  shall  be  taxed  as  a  pound.  The  tax  levied 
by  this  section  shall  be  represented  by  coupon  stamps;  and  the 
provisions  of  existing  laws  governing  the  engraving,  issue,  sale, 
accountability,  effacement,  and  destruction  of  stamps  relating  to 
tobacco  and  snuff,  as  far  as  applicable,  are  hereby  made  to  apply 
to  stamps   provided   for  by  this    section. 

Sec.  10.  That  whenever  any  manufacturer  of  filled  cheeese  sells 
or  removes  for  sale  or  consumption  any  filled  cheese  upon  which 
the  tax  is  required  to  be  paid  by  stamps,  without  paying  such  tax, 
it  shall  be  the  duty  of  the  Commissioner  of  Internal  Revenue, 
within  a  period  of  not  more  than  two  years  after  such  sale  or  re- 
moval, upon  satisfactory  proof,  to  estimate  the  amount  of  tax  which 
has  been  omitted  to  be  paid  and  to  make  an  assessment  therefor 
and  certify  the  same  to  the  collector.  The  tax  so  assessed  shall  be 
in  addition  to  the  penalties  imposed  by  law  for  such  sale  or  removal. 

Sec.  11.  That  all  filled  cheese,  as  herein  defined,  imported  from 
foreign  countries  shall,  in  addition  to  any  import  duty  imposed  on 
the  same,  pay  an  internal  revenue  tax  of  eight  cents  per  pound, 
such  tax  to  be  represented  by  coupon  stamps;  and  such  imported 
filled  cheese  and  the  packages  containing  the  same  shall  be  stamped, 
marked,  and  branded,  as  in  the  case  of  filled  cheese  manufactured 
in   the    United    States. 

Sec.  12.  That  any  person  who  knowingly  purchases  or  receives 
for  sale  any  filled  cheese  which  has  not  been  branded  or  stamped 
according  to  law,  or  which  is  contained  in  packages  not  branded 
or  marked  according  to  law,  shall  be  liable  to  a  penalty  of  fifty 
dollars   for  each   such   offense. 

Sec.  13.  That  every  person  who  knowingly  purchases  or  receives 
for  sale  any  filled  cheese  from  any  manufacturer  or  importer  who 
has  not  paid  the  special  tax  herein  provided  for  shall  be  liable, 
for  each  offense,  to  a  penalty  of  one  hundred  dollars,  and  to  a  for- 
feiture of  all  articles  so  purchased  or  received,  or  of  the  full  value 
thereof. 

Sec.  14.  That  whenever  any  stamped  package  containing  filled 
cheese   is   emptied   it    shall    be    the    duty  of    the    person    in    whose 


Dairy   Laws.  281 

hands  the  same  is  to  destroy  the  stamps  thereon;  and  any  person 
who  willfully  neglects  or  refuses  so  to  do  shall,  for  each  such 
offense,  be  fined  not  exceeding  fifty  dollars  or  imprisoned  not  less 
than  ten  days   nor  more   than   six  months. 

Sec.  15.  That  the  Commissioner  of  Internal  Revenue  is  author- 
ized to  have  applied  scientific  tests,  and  to  decide  whether  any 
substances  used  in  the  manufacture  of  filled  cheese  contain  ingre- 
dients deleterious  to  health.  But  in  case  of  doubt  or  contest,  his 
decision  in  this  class  of  cases  may  be  appealed  from  to  a  board 
hereby  constituted  for  the  purpose,  and  composed  of  the  Surgeon- 
General  of  the  Army,  the  Surgeon-General  of  the  Navy,  and  the 
Secretary  of  Agriculture,  and  the  decision  of  this  board  shall  be 
final   in  the   premises. 

Sec.  16.  That  all  packages  of  filled  cheese  subject  to  tax  under 
this  act  that  shall  be  found  without  stamps  or  marks  as  herein 
provided,  and  all  filled  cheese  intended  for  human  consumption 
which  contains  ingredients  adjudged  as  hereinbefore  provided  to  be 
deleterious  to  the  public  health,  shall  be  forfeited  to  the  United 
States. 

Sec.  17.    That   all   fines,    penalties   and   forfeitures   imposed   by  this 
act   may  be   recovered   in   any  court   of  competent  jurisdiction. 

Sec.  18.  That  the  Commissioner  of  Internal  Revenue,  with  the 
approval  of  the  Secretary  of  the  Treasury,  shall  make  all  need- 
ful regulations  for  the  carrying  into  effect  the  provisions  of  this 
act. 

Sec.  19.  That  this  act  shall  go  into  effect  on  the  ninetieth  day 
after  its  passage,  and  all  wooden  packages  containing  ten  or  more 
pounds  of  filled  cheese  found  on  the  premises  of  any  dealer  on 
and  after  the  ninetieth  day  succeeding  the  date  of  the  passage  of 
this  act,  shall  be  deemed  to  be  taxable  under  section  nine  of  this 
act,  and  shall  be  taxed,  and  shall  have  affixed  thereto  the  stamps, 
marks,  and  brands  required  by  this  act  or  by  regulations  made 
pursuant  to  this  act;  and  for  the  purpose  of  securing  the  aflftxing 
of  the  stamps,  marks,  and  brands  required  by  this  act,  the  filled 
cheese  shall  be  regarded  as  having  been  manufactured  and  sold  or 
removed  from  the  manufactory  for  consumption  or  use  on  or  after 
the  day  this  act  takes  effect;  and  such  stock  on  hand  at  the  time 
of  the  taking  effect  of  this  act  may  be  stamped,  marked,  and  branded 
under  special  regulations  of  the  Commissioner  of  Internal  Revenue, 
approved   by  the    Secretary  of  the   Treasury;    and    the    Commissioner 


282  Milk   and   Its   Products. 

of  Internal  Revenue  may  authorize  the  holder  of  such  packages  to 
mark  and  brand  the  same  and  to  affix  thereto  the  proper  tax-paid 
stamps. 

Approved  June  6,    1896. 

THE   NEW   YORK   LAW. 

The  law  of  the  state  of  New  York  is  typical  of  the  state  laws 
governing  the  manufacture,  sale,  and  adulteration  of  dairy  products. 
It  forms  Article  II.  of  Chapter  XXXIII.  of  the  General  Laws;  the 
latter  being  Chapter  338  of  the  Laws  of  1893,  passed  April  10th, 
J893,    and   is    as   follows: 

ARTICLE  II. 

Dairy    Products. 

Sec.  20.  Definitions.  —  The  terms  butter  and  cheese,  when  used 
in  this  article,  mean  the  products  of  the  dairy,  usually  known  by 
those  terms,  which  are  manufactured  exclusively  from  pure,  una- 
dulterated milk  or  cream  or  both,  with  or  without  salt  or  rennet, 
and  with  or  without  coloring  matter  or  sage.  The  terms  oleomar- 
garine, butterine,  imitation  butter  or  imitation  cheese,  shall  be 
construed  to  mean  any  article  or  substance  in  the  semblance  of 
butter  or  cheese  not  the  usual  product  of  the  dairy,  and  not  made 
exclusively  of  pure  and  unadulterated  milk  or  cream,  or  any  such 
article  or  substance  into  which  any  oil,  lard  or  fat  not  produced 
from  milk  or  cream  enters  as  a  component  part,  or  into  which 
melted  butter  or  butter  in  any  condition  or  state,  or  any  oil 
thereof,  has  been  introduced  to  take  the  place  of  cream.  The  term 
adulterated   milk,    when   so  used,   means: 

1.  Milk   containing  more   than   88   per  centum  of   water  or  fluids. 

2.  Milk   containing   less   than   12   per   centum   of  milk   solids. 

3.  Milk   containing  less   than   3   per   centum   of   fats. 

4.  Milk  drawn  from  cows  within  fifteen  days  before  and  five 
days   after   parturition. 

5.  Milk  drawn  from  animals  fed  on  distillery  waste,  or  any  sub- 
stance in  a  state  of  fermentation  or  putrefaction,  or  on  any  un- 
healthy  food. 

6.  Milk  drawn  from  cows  kept  in  a  crowded  or  unhealthy  conx 
dition. 


Dairy   Laws.  283 

7.  Milk  from  which  any  part  of  the  cream  has  been  removed. 

8.  Milk  which  has  been  diluted  with  water  or  any  other  fluid, 
or  to  which  has  been  added  or  into  which  has  been  introduced 
any   foreign   substance   whatever. 

All  adulterated  milk  shall  be  deemed  unclean,  unhealthy,  impure 
and  unwholesome.  The  terms  pure  milk  or  unadulterated  milk, 
when  used  singly  or  together,  mean  sweet  milk  not  adulterated,  and 
the  terms  pure  ci'eam  or  unadulterated  cream,  when  used  singly 
or  together,  mean  cream  taken    from   pure   and    unadulterated    milk. 

Sec.  21.  Care  and  feed  of  cows.  —  No  person  shall  keep  cows, 
for  the  production  of  milk  for  market  or  for  sale  or  exchange, 
or  for  manufacturing  the  milk  or  cream  from  the  same  into  any 
article  of  food,  in  a  crowded  or  unhealthy  condition,  or  feed  any 
such  cows  on  distillery  waste  or  on  any  substance  in  a  state  of 
putrefaction  or  fermentation,  or  upon  any  food  that  is  unhealthy, 
or  that  pi'oduces  impure,  unhealthy,  diseased  or  unwholsome  milk. 
But  this  section  shall  not  be  construed  to  prohibit  the  feeding  of 
ensilage. 

Sec.  22.  Prohibition  of  the  sale  of  adulterated  milk.  —  No  person 
shall  sell  or  exchange,  or  offer  or  expose  for  sale  or  exchange, 
any  unclean,  impure,  unhealthy,  adulterated  or  unwholesome  milk 
or  any  cream  from  the  same,  or  sell  or  exchange,  or  offer  or  expose 
for  sale  or  exchange,  any  article  of  food  made  from  such  milk,  or 
of  or  from  cream  from  the  same,  or  manufacture  from  any  such 
milk   or  cream  from  the   same,  any   article   of  food. 

Sec.  23.  Regulations  in  regard  to  butter  and  cheese  factories. — 
No  person  shall  sell,  supply  or  bring  to  be  manufactured  to  any 
butter  or  cheese  factory  any  milk  diluted  with  water,  or  any  un- 
clean, impure,  unhealthy,  adulterated  or  unwholesome  milk,  or  milk 
from  which  any  of  the  cream  has  been  taken,  except  pure  skim 
milk  to  skim-cheese  factories.  No  person  shall  sell,  supply  or 
bring  to  be  manufactured  to  any  butter  or  cheese  factorj'^  any  milk 
from  which  there  has  been  kept  back  any  part  of  the  milk  com- 
monly known  as  strippings,  or  any  milk  that  is  sour,  except  pure 
skim  milk  to  skim-cheese  factories.  The  owner  or  proprietor,  or  the 
persons  having  charge  of  any  butter  or  cheese  factory,  not  buying 
all  the  milk  used  by  him,  shall  not  use  for  his  own  benefit,  or 
allow  any  of  his  employes  or  any  other  person  to  use  for  his  own 
benefit,  any  milk,  cream,  butter  or  cheese  or  any  other  product 
thereof,  brought  to  such  factory,  without  the  consent  of  the  own- 
ers of  such  milk  or  the  products  thereof.    Every    butter  or  cheese 


284  Milk  and  Its  Products. 

manufacturer  not  buying  all  the  milk  he  uses,  shall  keep  a  cor- 
rect account  of  all  the  milk  daily  received,  of  the  number  of 
packages  of  butter  and  cheese  made  each  day,  and  the  number  of 
packages  and  aggregate  weight  of  cheese  and  butter  disposed  of 
each  day  ;  which  account  shall  be  open  to  inspection  to  any  per- 
son who  delivers   milk  to   such   factory. 

Sec.  24.  Cans  to  be  branded  with  the  name  of  county.  —  No 
person  shall  sell  or  offer  or  expose  for  sale  or  exchange  any  milk, 
except  in  the  county  where  produced,  unless  each  can,  vessel  or 
package  containing  such  milk  shall  be  distinctly  and  durably  branded 
with  letters  not  less  than  one  inch  in  length  and  of  a  suitable 
width  to  correspond  with  such  length,  and  with  suitable  spaces  be- 
tween the  letters,  on  the  outside,  above  the  center,  on  every  can, 
vessel  or  package  containing  such  milk,  the  Iname  of  the  county 
from  which  the  same  is  produced  ;  and  the  same  letters  shall  be 
branded  or  painted  in  a  conspicuous  place  on  the  carriage  or 
vehicle  in  which  the  milk  is  drawn  to  be  sold  ;  and  such  milk 
shall  not  be  sold  by  the  producer  outside  of  the  county  in  which 
it  is  produced,  except  in  or  out  of  a  can,  vessel,  package  or  car- 
riage or  vehicle  so  marked.  The  foregoing  prohibitions  and  provi- 
sions of  this  section  shall  not  apply  when  milk  is  sold  or  delivered 
in  glass  bottles.  No  milk  shall  be  sold  or  delivered  in  glass  bot- 
tles, except  in  the  county  where  produced,  unless  such  bottles 
shall  have  legibly  blown,  stamped,  engraved,  etched,  impressed  or 
moulded  in  the  glass,  or  otherwise  produced  upon  such  bottles,  the 
name  of  the  vendor,  or  the  same  is  on  a  label  or  cover  affixed 
thereto,  or  there  is  some  mark  or  device  on  or  affixed  to  such 
bottles  by  which  the  vendor  may  be  ascertained. 

Sec.  25.  Regulations  in  regard  to  condensed  milk. — No  condensed 
milk  shall  be  made  or  offered  or  exposed  for  sale  or  exchange  un- 
less manufactured  from  pure,  clean,  healthy,  fresh,  unadulterated 
and  wholesome  milk  from  which  the  cream  has  not  been  removed 
either  wholly  or  in  part,  or  unless  the  proportion  of  milk  solids 
shall  be  in  quantity  the  equivalent  of  12  per  centum  of  milk 
solids  in  crude  milk,  and  of  which  solids  25  per  centum  shall  be 
fats.  No  person  shall  manufacture,  sell  or  offer  for  sale  or  ex- 
change in  hermetically  sealed  cans,  any  condensed  milk  unless  put 
up  in  packages  upon  which  shall  be  distinctly  labeled  or  stamped 
the  name  of  the  person  or  corporation  by  whom  made,  and  the 
brand  by  which  or  under  which  it  is  made.  When  condensed  milk 
shall  be   sold  from  cans   or  packages  not    hermetically    sealed,    the 


Dairy   Laws.  285 

vendor  shall  brand  or  label  such  cans  or  packages  with  the  name 
of  the  manufacturer  of  the  milk   contained   therein. 

Sec.  26.  Mamifacture  and  sale  of  imitation  butter  prohibited. — 
No  person,  by  himself,  his  agents  or  employes,  shall  produce  or 
manufacture  out  of  or  from  any  animal  fats  or  animal  or  vegetable 
oils  not  produced  from  unadulterated  milk,  or  cream  from  the  same, 
any  article  or  product  in  imitation  or  semblance  of  natural  butter 
produced  from  pure,  unadulterated  milk  or  cream  of  the  same  ;  nor 
shall  any  person  solicit  or  take  orders  for  the  same,  or  offer  the 
same  for  sale,  or  mix,  compound  with  or  add  to  milk,  cream  or 
butter  any  acids  or  other  deleterious  substance,  or  any  animal  fats 
or  animal  or  vegetable  oils  not  produced  from  milk  or  cream,  so 
as  to  produce  any  article  or  substance,  or  any  human  food  in  imi- 
tation or  in  semblance  of  natural  butter,  nor  sell,  keep  for  sale  or 
offer  for  sale  any  article,  substance  or  compound  made,  manufac- 
tured or  produced  in  violation  of  the  provisions  of  this  section, 
whether  such  article,  substance  or  compound  shall  be  made  or  pro- 
duced  in  this   state   or  elsewhere. 

Sec.  27,  Manufacture  of*  mixing  of  animal  fats  with  milk, 
cream  or  butter  prohibited. — No  person  shall  manufacture,  mix,  or 
compound  with  or  add  to  natural  milk,  cream  or  butter  any  ani- 
mal fats  or  animal  or  vegetable  oils,  nor  make  or  manufacture  any 
oleaginous  substance  not  produced  from  milk  or  ci-eam,  with  intent 
to  sell  the  same  as  butter  or  cheese  made  from  unadulterated  milk 
or  cream  or  have  the  same  in  his  possession  with  such  intent ;  nor 
shall  any  person  solicit  or  take  orders  for  the  same  or  offer  the 
same  for  sale,  nor  shall  any  such  article  or  substance  or  compound, 
so  made  or  produced,  be  sold  as  and  for  butter  or  cheese,  the  pi*o- 
duct  of  the  dairy.  No  person  shall  coat,  powder  or  color  with 
annatto  or  any  coloring  matter  whatever,  butterine  or  oleomargarine 
or  any  compound  of  the  same,  or  any  product  or  manufacture 
made  in  whole  or  in  part  from  animal  fats  or  animal  or  vege- 
table oils  not  produced  from  tmadulterated  milk  or  cream  by  means 
of  which  such  product,  manufacture  or  compound  shall  resemble 
butter  or  cheese,  the  product  of  the  dairy  ;  nor  shall  he  have  the 
same  in  his  possession  with  intent  to  sell  the  same,  nor  shall  he 
sell   or   offer  to   sell  the   same. 

Sec.  28.  Prohibited  articles  not  to  be  furnished. — Nor  keeper  or 
proprietor   of   any   bakery,   hotel,   boarding-house,   restaurant,    saloon, 


*^So  in  the  original. 


286  Milk   and   Its   Products. 

lunch-counter  or  place  of  public  entertainment,  or  any  person  hav- 
ing charge  thereof  or  employed  thereat,  or  any  person  furnishing 
board  for  any  others  than  members  of  his  own  family,  or  for  any 
employes  where  such  board  is  furnished  for  a  compensation  or  as 
part  of  the  compensation  of  any  such  employe,  shall  keep,  use  or 
serve  therein,  either  as  food  for  his  guests,  boarders,  patrons,  cus- 
tomers or  employes,  or  for  cooking  purposes,  any  article  or  sub- 
stance made   in  violation  of  the  provisions   of  this   article. 

Sec.  29.  Cse  of  coloring  matter  prohibited.  —  No  person  manu- 
facturing with  intent  to  sell  any  substance  or  article  in  imitation 
or  semblance  of  butter  or  cheese  not  made  exclusively  from  un- 
adulterated milk  or  cream,  or  both,  with  salt  or  rennet,  or  both,  and 
with  or  without  coloring  matter  or  sage,  but  into  which  any  animal, 
intestinal  or  oflfal  fats,  or  any  oils  or  fats  or  oleaginous  substance 
of  any  kind  not  produced  from  from*  pure,  unadulterated  milk  or 
cream,  or  into  which  melted  butter,  or  butter  in  any  condition  or 
state  or  any  modification  of  the  same,  or  lard  or  tallow  shall  be 
introduced,  shall  add  thereto  or  combine  therewith  any  annatto  or 
compounds  of  the  same,  or  any  other  substance  or  substances  what- 
ever, for  the  purpose  or  with  the  effect  of  imparting  thereto  a 
color  resembling  yellow,  or  any  shade  of  yellow  butter  or  cheese, 
nor  introduce  any  such  coloring  matter  or  other  substance  into  any 
of  the   articles   of  which   the   same   is   composed. 

Sec.  30.  Manufacture  and  sale  of  imitation  cheese  prohibited. —  No 
person  shall  manufacture,  deal  in,  sell,  offer  or  expose  for  sale  or 
exchange  any  article  or  substance,  in  the  semblance  of  or  in  imi- 
tation of  cheese  made  exclusively  of  unadulterated  milk  or  cream, 
or  both,  into  which  any  animal,  intestinal  or  offal  fats  or  oils,  or 
melted  butter  or  butter  in  any  condition  or  state  or  modification  of 
the  same,  or  oleaginous  substances  of  any  kind  not  produced  from 
unadulterated  milk   or  cream,  shall  be  introduced. 

Sec.  31.  When  prohibitions  do  not  apply  to  skim  milk  or  skim 
cheese. — Except  in  the  counties  of  New  York  and  Kings,  the  pro- 
hibitions contained  in  this  article  against  the  sale  of  adulterated 
milk  shall  not  apply  to  skim  milk  which  is  clean,  pure,  healthy, 
wholesome  and  unadulterated,  except  by  skimming,  sold  for  use  in 
the  county  in  which  it  is  produced  or  an  adjoining  county,  if  it 
is  sold  for  and  as  skimmed  milk.  The  prohibitions  in  this  article 
against  the   sale   of  cheese  made   from  unadulterated  milk   or  cream 

*So  in  the  original. 


Dairy   Laws.  287 

shall  not  apply  to  pure  skim  cheese  made  from  milk  which  is 
clean,  pure,  healthy,  wholesome  and  unadulterated,  except  by  skim- 
ming. 

Sec.  32.  Packages  to  he  branded  with  name  of  maker. — No  man- 
ufacturer of  receptacles  for  the  package  of  butter  shall  sell  or  dis- 
pose of  any  such  receptacle  without  branding  his  name  and  the 
true  weight  of  the  receptacle  upon  the  same  with  legible  letters  or 
figures  not  less  than  one-quarter  of  an  inch  in  length.  No  person 
shall  sell,  or  offer  for  sale,  any  package  containing  butter  or  lard 
packed  by  him  unless  the  true  weight  thereof,  with  the  initial  let- 
ters of  the  name  of  the  person  packing  such  butter  or  lard,  be 
marked  or  stamped  in  a  legible  manner  on  the  side  or  head  of  such 
package. 

Sec.  33.  Manufacturer's  brand  of  cheese.  —  Every  manufacturer 
of  full  milk  cheese  may  put  a  brand  upon  each  cheese  indicating 
"full  milk  cheese,"  and  the  date  of  the  month  and  year  when 
made,  and  no  person  shall  use  such  a  brand  upon  any  cheese  made 
from  milk  from  which  any  of  the  cream  has  been  taken.  The 
Commissioner  of  Agriculture  shall  procure  and  issue  to  the  cheese 
manufacturers  of  the  state,  on  proper  application  therefor,  and  under 
such  regulations  as  to  the  custody  and  use  thereof  as  he  may  pre- 
scribe, a  uniform  stencil  brand,  bearing  a  suitable  device  or  motto, 
and  the  words,  "New  York  state  full  cream  cheese."  Every  such 
brand  shall  be  used  upon  the  outside  of  the  cheese  and  upon  the 
package  containing  the  same,  and  shall  bear  a  different  number  for 
each  separate  factory.  The  Commissioner  shall  keep  a  book,  in 
which  shall  be  registered  the  name,  location  and  number  of  each 
manufactory  using  the  brand,  and  the  name  or  names  of  the  per- 
sons at  each  manufactory  authorized  to  use  the  same.  No  such 
brand  shall  be  used  upon  any  other  than  full-cream  cheese  or  pack- 
ages  containing  the   same. 

Sec.  34.  Use  of  false  brand  prohibited.  —  No  person  shall  offer, 
sell,  or  expose  for  sale,  in  any  package,  butter  or  cheese  which  is 
falsely  branded   or  labeled. 

Sec.  35.  County  trade-marks. — At  a  regular  or  special  meeting 
of  a  county  dairyman's  association  in  any  county  of  the  state  there 
may  be  adopted  a  county  trade-mark,  by  a  majority  of  the  mem- 
bers   present    and    voting,    to    be    used     as    a    trade-mark     by     am* 

*So  in  the  original. 


288  Milk   and  Its   Products. 

person  manufacturing  pure  unadulterated  butter  or  full-cream  cheese 
in  such  county.  The  secretary  of  the  association  shall  forthwith 
send  to  the  Commissioner  of  Agriculture  a  copy  of  such  trade-mark, 
which  copy  he  shall  place  on  file  in  his  office,  noting  thereupon  the 
day  and  hour  he  received  the  same.  But  one  county  trade-mark 
for  butter  and  for  cheese  shall  be  placed  on  file  for  the  same 
county.  No  association  shall  adopt  any  trade-mark  of  any  county 
already  on  file,  or  use  that  of  any  other  county  in  the  formation 
of   a  trade-mark. 

Sec.  36.  Object  and  intent  of  this  article.  — This  article  and  each 
section  thereof  are  declared  to  be  enacted  to  prevent  deception  in 
the  sale  of  dairy  products,  and  to  preserve  the  public  health,  which 
is  endangered  by  the  manufacture,  sale  and  use  of  the  articles  or 
substances   herein   regulated   or   prohibited. 

Sec.  37.  Penalties.  —  Every  person  violating  any  of  the  provisions 
of  this  article  shall  forfeit  to  the  people  of  the  state  of  New  York 
the  sum  of  one  hundred  dollars  for  every  such  violation.  When 
such  violation  consists  of  the  manufacture  or  production  of  any 
prohibited  article,  each  day  during  which  or  any  part  of  which  such 
manufacture  or  production  is  carried  on  or  continued  shall  be 
deemed  a  separate  violation  of  the  provisions  of  this  article.  When 
the  violation  consists  of  the  sale,  or  the  offering  or  exposing  for 
sale  or  exchange  of  any  prohibited  article  or  substance,  the  sale  of 
each  one  of  several  packages  shall  constitute  a  separate  violation, 
and  each  day  on  which  any  such  article  or  substance  is  offered  or 
exposed  for  sale  or  exchange  shall  constitute  a  separate  violation  of 
this  article.  When  the  use  of  any  such  article  or  substance  is 
prohibited,  each  day  during  which  or  any  part  of  which  said  article 
or  substance  is  so  used  or  furnished  for  use  shall  constitute  a 
separate  violation,  and  the  furnishing  of  the  same  for  use  to  each 
person  to  whom  the  same  may  be  furnished  shall  constitute  a 
separate   violation. 


References.  289 

D.     BEFEBENCES   TO    AGBICULTUBAL    EXPEBIMENT 
STATION  BEPORTS  AND   BULLETINS. 

The  following  references  will  aid  the  student  who  desires  to  make 
a  more  thorough  study  of  the  subjects  discussed.  They  are  taken 
wholly  from  the  literature  of  American  agricultural  investigations, 
and  include  only  some  of  the  more  important  articles.  The  Experi- 
ment Station  Record  and  the  Handbook  of  Experiment  Station  Work, 
both  issued  by  the  U.  S.  Department  of  Agriculture,  contain  many 
condensed   results   of   dairy   investigation. 


Chapter  I. 

Studies   in  Milk   Secretion.       Indiana   Bull.    No.    24,    pp.    13-16. 
How   is   Milk   Formed?      Nevada   Bull.    No.    16,    pp.    4-5. 
Elaboration   of   Milk.       Ontario   Kept,    for   1893,    pp.    165-166. 
Dividing   Milkings.      Indiana   Bull.    No.    24,    pp.    10-13. 
Milking    Two    and    Three    Times    per    Day.      Vermont    Rept.    for 
1890,   pp.    90-96. 

Chapter  II. 

The   Composition   of   Milk.       Ontario   Bull.    No.    XXXIX. 

The  Mineral  Ingredients  of  Milk.  Maine  Rept.  for  1890,  part 
II.,   pp.    52-57. 

The  Constitution  of  Milk,  and  Some  of  the  Conditions  which 
Affect  the    Separation   of   Cream.      Wisconsin   Bull.    No.    18. 

Conditions  Affecting  the  Consistency  of  Milk.  Wisconsin  Rept. 
for   1896,    pp.    73-80. 

Chemistry  of  Dairy  Products.      Ontario  Rept.  for  1890,  pp.  237-241. 

Milk  Analysis.       Connecticut  Rept.  for  1886,  pp.  119-130. 

Investigations  Relating  to  the  Composition  of  Milk.  Wisconsin 
Rept.  for  1890,  pp.  114-119. 

Fibrin  in  Milk.      Wisconsin  Rept.  for  1893,  pp.  143-145. 

Relation  of  Fat  and  Casein  in  Milk.  Vermont  Rept.  for  1890,  pp. 
97-100. 

The  Composition,  Creaming  and  Churning  of  Colostrum.  Vermont 
Rept.  for  1891,  pp.  104-108. 

The  Fat  Globules  of  Milk.  New  York  Rept.  for.  1885,  pp.  266- 
275;  Wisconsin  Rept.  for  1894,  pp.  223-239;  Ontario  Rept.  for  1885, 
pp.  127-130. 

S 


290  MilJc   and   Its   Products. 

The  Effects  of  Feed  Upon  the  Quality  of  Milk.  Iowa  Bull.  No.  14, 
pp.  123-142  ;  New  Hampshire  Rept.  for  1893,  pp.  138-155,  and  Bull, 
No.  9;  Bull.  No.  16;  Bull.  No.  Ig  ;  Bull.  No.  20. 

Tests  of  Several  Breeds  of  Dairy  Cows.  A  Study  of  Dairy  Pro- 
ducts. Maine  Rept.  for  1889,  pp.  106-134.  The  test  is  continued  in 
Rept.  for  1890,  Part  II.,  pp.  17-42. 

Corn  Silage  for  Milch  Cows.  New  York  (State)  Bull.  No.  97, 
New  Series. 

Investigations  of  the  Several  Breeds  of  Dairy  Cattle.  New  York 
(State)  Reports  for  1891,  1892,  1893,  1894. 

On  the  Effects  of  Feeding  Fat  to  Cows.  New  York  (Cornell) 
Bull.  No.  92. 

Variations  in  Milk.     Illinois  Bull.  No.  17,  pp.  9-16,  and  Bull.  No.  24. 

The  Influence  of  Advancing  Lactation  upon  the  Production  of  But- 
ter and  Cheese.       New  York  (State)  Rept.  for  1891,  pp.  369-389. 

Effects  of  Drouth  upon  Milk  Production.  New  York  (State)  Bull. 
No.  105.       New  Series. 

Variations  in  Milk.       Vermont  Rept.  for  1891,  pp.  61-74. 

Variations  in  Quantity  and  Quality  of  Milk.  Vermont  Rept.  for 
1892,  pp.  90-119,  and  Bull.  No.  38. 

The  Composition  of  Milk  as  Affected  by  Methods  of  Milking. 
Wisconsin  Rept.  for  1889,  pp.  44,  51,  61. 

Chapter  III. 

Milk  Tests.     (Short,  Lactoscope.)     Illinois  Bull.  No.  9,  pp.  293-302 

Investigation  of  Milk  Tests.  (Short,  Parsons,  Failyer  and  Willard 
Cochran,  Patrick,)  Illinois  Bull.  No.  10. 

Milk  Tests  :  Methods  of  Testing  Milk.  (Patrick,  Babcock,  Beim 
ling.  Gravimetric.)       Illinois  Bull.  No.  14,  pp.  462-467. 

Methods  of  Testing  Milk.  (Short,  Patrick,  Cochran,  Babcock 
Beimling.)       West  Virginia  Bull.  No.  13,  pp.  41-63. 

Testing  Milk.  (Short,  Patrick,  Cochran,  Babcock,  Soxhlet,  Beim 
ling.)     West  Virginia  Report  for  1890,  pp.  68-88. 

A  New  Volumetric  Method  for  the  Estimation  of  Fat  in  Milk 
Skimmed  Milk,  Buttermilk  and  Cream.  (Parsons.)  New  Hampshire 
Report  for  1888,  pp.  69-83. 

Babcock  and  Beimling  Tests.  Ontario  Report  for  1891,  pp.  183- 
184. 

Simple  Methods  of  Determining  Milk  P^at.  (Short,  Cochran,  Gravi- 
metric.)    Pennsylvania  Bull.  No.  12. 


References.  291 

Comparative  Test  of  Machines  and  Methods  for  the  Determination 
of  Fat  in  Milk.  (Short,  Beimling,  Patrick,  Babcock,  Gravimetric.) 
Mississippi  Bull.  No.  15,  pp.  5-16. 

A  Description  of  Cochran's  Method  for  the  Determination  of  Fat 
in  Milk,  for  the   Use   of  Dairymen.      New    York  (Cornell)  Bull.  No. 

XVII. 

Iowa  Station  Milk  Test.  (Patrick).  Iowa  Bull.  No.  8,  pp.  295- 
316  ;  No.  9,  p.  355  ;  No.  11,  pp.  484-487. 

A  New  Method  for  Determining  the  Amount  of  Butter  Fat  in 
Milk.     Mississippi  Bull.  No.  21,  pp.  17-19. 

A  New  Milk  Test.     (Beimling).     Vermont  Bull.  No.  21. 

The   Lactanalyt,  A   New   Milk   Tester.      Vermont   Report   for   1894, 

pp.  161-162. 

A  New  Method  of  Milk  Analysis  (Short)  for  the  Use  of  Dairy- 
men, and  a  Comparison  of  Its  Results  with  those  Obtained  by  the 
Churn.     Kansas  Report  for  1888,  pp.  149-164. 

A  Method  for  the  Determination  of  Fat  in  Milk  and  Cream, 
(Parsons.)     New  York  (State)  Bull.  No.  19.     New  Series. 

Feser's  Lactoscope  and  Fjord's  Centrifugal  Controller,  described 
in  Ontario  Report  for  1885,  pp.  207-208. 

Testing  Milk  at  Creameries.     (Short.)     Vermont  Bull.  No.  16. 

The  Schoch  and  Bolender  Test  Churn.  Wisconsin  Report  for 
1884,  pp.   23-25. 

Description  of  the  Test  Churn.     Ontario  Report  for  1885,  p.  201. 

The  Oil  Test  for  Cream.     Wisconsin  Bull.  No.  12. 

A  New  Method  for  Determining  Fat  in  Milk.  (Short.)  Wiscon- 
sin Bull.  No.  16  and  Report  for  1888,  pp.  124-136. 

The  Babcock  Milk  Test  was  first  described  in  Wisconsin  Bull. 
No.  24  and  Report  for  1890,  pp.  98-113.  Improvements  and  modifi- 
cations are  discussed  in  Bull.  No.  31,  pp.  3-16;  Bull  No.  36,  pp. 
3-20  ;  Bull  No.  52,  Report  for  1892,  pp.  219-244  ;  Report  for  1893, 
pp.  116-121.  Compared  with  the  Gravimetric  Method  in  Report  for 
1896,  pp.  138-143. 

Elsewhere,  the  method  has  been  described  in  Pennsylvania  Bull. 
No.  33  ;  Washington  Bull.  No.  18  ;  New  York  (Cornell)  Bull.  No.  29, 
pp.  77-80  ;  Colorado  Bull.  No.  20,  pp.  3-10  ;  North  Carolina  Bull.  No. 
113,  pp.  101-111  ;  West  Virginia  Bull.  No.  13,  pp.  52-57  ;  Ontario  Bull. 
No.'  LXI.  ;  Bull.  No.  XCIIL,  pp.  5-6  ;  Connecticut  Bull.  No.  106,  pp. 
2-9  ;  Bull  No.  108,  pp.  5-11  ;  Bull  No.  117,  Report  for  1894,  pp.  209- 
244  ';  Maine  Bull.  No.  3,  Second  Series  ;  Bull  No.  4,  Report  for  1891, 
Part  II.,  pp.  71-80;  Michigan  Bull.  No.  127;  Illinois  Bull.  No.  27; 
North   Dakota   Bull.  No.  22  ;    Pennsylvania  Report   for   1895,    Part  II., 


292  Milk   and   Its   Products. 

pp.  90-100  ;  Nevada  Bull.  No.  16,  pp.  41-51 ;  Mississippi  Bull.  No.  15, 
pp.  7-14. 

Milk  Sampling.     Delaware  Bull.  No.  XXXI. 

Composite  Milk  Samples  Tested  for  Butter  Fat.  Illinois  Bull. 
No.  16,  pp.  504-515.     Continued  in  Bull.  No.  18,  pp.  27-28. 

The  Composite  Sample.  Preservatives  for  Keeping  Milk— Samples 
for  Testing.     Iowa  Bull.  No.  11,  pp.  482^84. 

Composite  Samples  at  the  Creamery  —  Chromate  Preservatives. 
Iowa  Bull.  No.  22,  pp.   836-844. 

Detection  of  Adulterations  in  Milk.  Wisconsin  Bull.  No.  31,  pp. 
17-27;  Bull.  No.  36,  pp.  21-31,  and  Report  for  1892,  pp.  245-257. 
Ontario  Bull.  No.  XCIII.,  pp.  3-5  ;  Vermont  Newspaper  Bull.  No.  4, 

Lactometer  and  Milk  Test  for  Examining  Milk.  Minnesota  Bull 
No.  27,  pp.  55-56. 

The  Relation  between  Specific  Gravity  and  Solids  of  Milk.  Wis 
cousin  Report  for  1895,  pp.  120-126. 

The  Estimation  of  the  Total  Solids  in  Milk  from  the  Per  Cent 
of  Fat,  and  the  Specific  Gravity  of  the  Milk.  Wisconsin  Report  for 
1891,  pp.  292-307,  and  Report  for  1893,  p.  142. 

The  Lactometer  and  Fat  Test  for  Cheese  and  Condensed  Milk 
Factories      Maine  Bull.  No.  4,  New  Series,  pp.  6-10. 

Chapter  IV. 

Dairy  Bacteriology.  U.  S.  Dept.  Agr.  Ofiice  of  Expt.  Stations. 
Bull.  No.  25. 

The  Fermentations  of  Milk.  U.  S.  Dept,  Agr.  Expt.  Stations. 
Bull.  No.  9. 

Souring  of  Milk.     U.  S.  Dept.  Agr.     Farmers'  Bull.  No.  29. 

Milk  Fermentations  and  Their  Relations  to  Dairying.  U.  S.  Dept. 
Agr.     Farmers'  Bull.  No.  9. 

The  Isolation  of  Rennet  from  Bacteria  Cultures.  Connecticut 
(Storrs)  Report  for  1892,  pp.  106-126. 

The  Sources  of  Bacterial  Infection,  and  the  Relation  of  the  Same 
to  the  Keeping  Quality  of  Milk.  Wisconsin  Report  for  1894,  pp. 
150-165. 

Cleanliness  in  Handling  Milk  ;  Bacteriological  Considerations. 
North  Dakota  Bull.  No.  21. 

A  Microccus  of  Bitter  Milk.  Connecticut  (Storrs)  Report  for 
1891,  pp.    158-162. 

Pasteurization  of  Milk  and  Cream  for  Direct  Consumption.  Wis- 
consin Bull.  No.  44. 


Befermces.  293 

Notes  on  Pasteurization  of  Milk  and  Cream.  Wisconsin  Report 
for  1895,  pp.  158-173. 

On  the  Restoration  of  the  Consistency  of  Pasteurized  Milk  and 
Cream.    Wisconsin  Report  for  1896,  pp.  81-94,  and  Bull.  No.  54. 

A  Preliminary  Bulletin  on  Pasteurization  of  Milk.  Michigan  Bull. 
No.  134. 

Preservation  of  Cream  for  Market.  Maine  Bull.  No.  23,  New 
Series. 

Chapter  V. 

Aeration  and  Aerators.  New  York  (Cornell)  Bull.  No.  39,  pp. 
90-94. 

Aeration  of  Milk.     Vermont  Report  for  1892,  pp.  123-128. 

Concerning  the   Aeration  of  Milk.     Indiana  Bull.  No.  44,  pp.  37-39. 

Town  and  City  Milk  Supply.  U.  S.  Dept.  Agr.  Farmers'  Bull. 
No.  42,  pp.  23-28. 

Variations  in  Fat  of  Milk  Served  to  Customers  in  Dipping  from 
Cans.     New  York  (Cornell)  Bull.  No.  XX.,  pp.  G8-71. 

Variations  in  the  Fat  of  Milk.     Ontario  Bull.  No.  LXVI. 


Chapter  VI. 

Cream  Raising  by  Dilution.  New  York  (  Cornell )  Bull.  No.  20, 
pp.  61-67  ;  Bull.  No.  29,  pp.  65-71  ;  Bull.  No.  39,  pp.  77-85  ;  Illinois 
Bull.  No.  12,  pp.  376-377  ;  Bull.  No.  18,  pp.  30-32  ;  Vermont  Rept.  for 
1890,  pp.  100-107. 

Other  Methods  of  Setting  Milk.  Minnesota  Bull.  No.  19,  pp.  11- 
19;  Iowa  Bull.  No.  25,  pp.  39-40;  Indiana  Bull.  No.  44,  pp.  23-37;  Wis- 
consin Rept.  for  1884,  pp.  17-22;  Rept.  for  1893,  pp.  147-150;  Bull. 
No.  7,  pp.  9-13  ;  Bull.  No.  29  ;  Canada,  Central  Experimental  Farm 
Rept.  for  1891,  pp.  89-104  ;  Rept.  for  1892,  pp.  71-74  ;  Ontario  Rept. 
for  1894,  pp.  142-144 ;  Vermont  Rept.  for  1891,  pp.  100-101  ;  Maine 
Bull.  No.  5,  Second  Series  ;  Utah  Bull.  No.  42. 

The  Viscosity  of  Milk.     New  York  (State)  Rept.  for  1886,  pp.  323-330. 

The  Constitution  of  Milk,  and  Some  of  the  Conditions  Which  Affect 
the  Separation  of  Cream.      Wisconsin  Bull.  No.  18. 

The  Centrifugal  Separation  of  Casein  and  Insoluble  Phosphates  from 
Milk.      Wisconsin  Rept.  for  1895,  pp.  93-99. 

Tests  of  Cream  Separators.  Delaware  Bull.  No.  17,  and  Rept.  for 
1892,  pp.  110-122  ;  Iowa  Bull.  No.  25,  pp.  32-38  ;  New  Hampshire  Rept. 
for  1893,  pp.  36-45  and  Bull.  No.  7;  New  York  (Cornell)  Bull.  No.  66 
and  105;    North  Carolina  Bull.   No.    114;  Pennsylvania  Rept.    for  1892 


294  3nik   and  Its   Products. 

part  II.,  pp.  51-79,  and  Bull.  No.  20;  Bull.  No.  27,  Rept.  for  1894, 
pp.  13-35;  South  Dakota  Bull.  No.  39;  Vermont  Bull.  No.  27,  and 
Rept.  for  1892,  pp.  13G-143;  Rept.  for  1893,  pp.  92-100;  Rept.  for 
1894,  pp.  151-160;  Wisconsin  Rept.  for  1895,  pp.  151-157,  and  Bull. 
No.  46 


Chapters  VII.,  VIII.,  IX. 

Experiments  with  Boyd's  Vat  and  Starter.  Ontario  Rept.  for  1891 
pp.  178-179. 

Bacteria  in  the  Dairy.  Connecticut  (Storrs)  Rept.  for  1895,  pn 
14^1.  ^ 

The  Use  of  Bacterial  Culture  Starters  in  Butter  Making,  With 
Especial  Reference  to  the  Conn  Culture  (  B.  41).  Wisconsin  Rept.  for 
1895,  pp.  174-231;  published,  in  part,  in  Bull.  No.  48. 

An  Acid  Test  of  Cream.  Illinois  Bull.  No.  32,  and  Bull.  No  33 
pp.  399-400. 

The  Alkaline  Tablet  Test  of  Acidity  in  Milk  or  Cream.  Wisconsin 
Bull.  No.  52,  pp.  8-16. 

Sweet  Versus  Sour  Cream  Butter.  Iowa  Bull.  No.  8,  pp.  317-320; 
Bull.  No.  11,  pp.  481-482  ;  Bull.  No.  18,  pp.  478-487  ;  Bull.  No.  21,  pp'. 
788-791;  Illinois  Bull.  No.  9,  pp.  301-302;  Texas  Bull.  No.  11,  pp. 
15-16;  Ontario  Rept.  for  1891,  pp.  179-181;  West  Virginia  Rept.  for 
1890,   pp.  48-66. 

Creamery  Studies  of  Methods  and  Machinery.  A  comparison 
of  the  Sour  Cream,  Sweet  Cream  and  Butter  Extractor  Processes 
Delaware  Rept."  for  1890,  pp.  17-23,  and  pp.  129-149;  also  Bull" 
No.  IX. 

Our  Experience  with  Extractor  Butter.  Ontario  Rept.  for  1893 
pp.  170-171.  ' 

A  Study  in  Churning.      Iowa  Bull.  No.  22,  pp.  819-832. 

Churning  Experiments.       Vermont  Rept.  for  1893,  pp.  100-106. 

Butter  Tests.  New  York  (State)  Rept.  for.  1884,  pp.  334-347,  and 
Rept.  for  1885,  pp.  275-292. 

The  Effect  of  Succulent  Food  Upon  the  ChurnabUity  of  the  Fat  in 
Milk.       Vermont  Rept.  for  1890,  pp.  70-74. 

Butter  Making.  Ontario  Rept.  for  1889,  pp.  161-163;  Bull.  No 
XLVIII. 

Canada  Central  Experimental  Farm  Dairy.       Bull.  No.  3. 

Washing  and  Salting  Butter.      Minnesota  Bull.  No.  7,  pp.  34-42. 


Eeferences.  295 

Chapters   X.,  XI. 

For  references  to  aeration,  see  Chapter  V. 

Points  of  Attention  for  the  Patrons  of  Cheese  Factories  and  Cream^ 
eries.       Ontario  Bull.  No.  II. 

Milk  for  Cheese  Making.  Ontario  Bull.  *No.  XLI.;  Bull.  No. 
XXVIII. ;  Bull.  XCIV. ;  Canada  Central  Experimental  Farm  Dairy. 
Bull.  No.  1. 

Pure  Lactic  Culture  of  Bacteria  in  Cheese  Making.  Wisconsin  Rept. 
for  1896,  pp.  112-126. 

Rennet  Extracts  of  Commerce.       Iowa  Bull.  No.  22,  pp.  845-851. 

Losses  in  Cheese  Making.       Vermont  Rept.  for  1891,  pp.  95-100. 

The  Effect  of  Salt  Upon  Cheese.  Wisconsin  Rept.  for  1894,  pp. 
220-222. 

The  Effect  of  Aeration  on  the  Flavor  of  Tainted  Curds  in  Cheese 
Making.  The  Influence  of  Acid  on  the  Texture  of  Cheese.  The  Hot 
Iron  Test.  Experiments  in  Ripening  the  Milk  before  Setting.  Wis- 
consin  Rept.  for  1895,  pp.  127-138. 

Experiments  in  the  Manufacture  of  Cheese.  New  York  (  State ) 
Repts.  for  1891,  p.  216;  1892,  p.  295;  1893,  p.  239;  1894,  p.  263. 

Hints  to  Cheese  Makers.       Iowa  Bull.  No.  19,  pp.  627-631. 

Investigations  in  Cheese  Making.      Iowa.  Bull.  No.  21,  pp.  735-767. 

Experiments  in  Cheese  Making.  Minnesota  Bull.  No.  19,  pp. 
20-25. 

Experiments  in  the  Manufacture  of  Cheese.  Wisconsin  Rept.  for 
1894,  pp.  131-149. 

The  Relation  Between  Milk  Solids  and  the  Yield  of  Cheese.  Wis- 
consin Rept.  for  1895,  pp.  100-119. 

Notes  for  Cheese  Makers  for  May.  Ontario  Bull.  No.  XL. ;  for  July, 
Bull.  No.  XLIIL;  for  August,  Bull.  No.  XLIV. ;  for  October,  Bull. 
No.  XLVII.      Rept.  for  1889,  pp.  163-179. 

Notes  for  Cheese  Makers  for  May.  Canada  Central  Experimental 
Farm,  Dairy  Bull.  No.  2;  Special  Dairy  Bulletins  for  July,  August, 
October  and  June. 

Articles  on  Spring,  Summer  and  Fall  Cheese  in  Ontario  Rept.  for 
1893,  pp.  167-170. 

Gas  Producing  Bacteria,  and  the  Relation  of  the  Same  to  Cheese. 
Wisconsin  Rept.  for  1895. 

The  Rise  and  Fall  of  Bacteria  in  Cheddar  Cheese.  Wisconsin  Rept. 
for  1896,  pp.  95-111. 

An  Aromatic  Bacillus  of  Cheese.       Iowa  Bull.  No.  21,  pp.  792-796. 

Changes  During  Cheese  Ripening.       Iowa  Bull.  No.  24,  pp.  969-984. 


296  Milk   and   Its   Products. 

Moisture  Supply  in  Cheese  Curing  Rooms.  Wisconsin  Rept.  for 
1896,  pp.    156-163. 

Experiments  Upon  the  Curing  of  Cheese.  Cornell  University  Agr. 
Exp.  Sta.  Rept.  for  1880,  pp.  9-27. 


Chapter  XIL 

The  Manufacture  of  Sweet  Curd  Cheese  (Edam  and  Gouda).  Min- 
nesota Rept.  for  1894,  pp.  104-128,  and  Bull.  No.  35. 

Experiment  Relating  to  the  Manufacture  of  Edam  and  Gouda  Cheese. 
New  York  (State)  Rept.  for  1893,  pp.  244-209,  and  Bull.  No.  50. 

Albumin  Cheese.      Wisconsin  Rept.  for  1895,  pp.  134-136. 

Chapter  XIII. 

The  Manufacture  of  Milk  Sugar  (Report  of  Chemist).  Delaware 
Report  for  1891,  pp.  104-108. 

The  Hog  as  an  Adjunct  to  the  Dairy.  Ontario  Report  for  1889, 
pp.  184-189. 

Whey  Butter.     New  York  (Cornell)  Bull.  No.  85. 

Sweet  Skim  Milk ;  Its  Value  as  Food  for  Pigs  and  Calves. 
Wisconsin  Bull.  No.  1. 

The  Feeding  Value  of  Whey.  Wisconsin  Bull.  No.  27,  Report 
for  1891,  pp.  38-48. 

Feeding  Waste  Products  of  the  Dairy.  Wisconsin  Report  for 
1886,  pp.  21-25. 

The  Value  of  Creamery  Separator  Skim  Milk  for  Swine  Feeding. 
Wisconsin  Report  for  1895,  pp.  7-23. 


Chapter  XIV. 

Building   Creameries    and    Organization    of    Cooperative    Creamery 
Companies.     South  Dakota  Bull.  No.  46. 

Creameries   for  Texas  ;  Plans  and  Specifications  in  Full  for  Cream- 
ery Outfit.     Texas  Bull.  No.  5. 

Cooperative   Creameries.       Minnesota   Report   for   1894,  pp.    93-103, 
and  Bull.  No.  35. 

The   Establishment  of   Cheese   Factories   and   Creameries.     Special 
Bull,  of  the  Central  Canada  Experimental  Farm,  Ottawa. 

By-Laws,  Rules   and   Regulations   for   Cheese   Factories.      Canada 
Central  Experimental  Farm  Dairy  Bull.  No.  9. 


References.  297 

By-Laws,  Rules   and  Regulations    for    Creameries    on    the    Cream- 
Gathering  Plan.     Central  Experimental  Farm,  Dairy  Bull.  No.  10. 


Chapter  XV. 

Statistics  of  the  Dairy.  U.  S.  Dept.  Agr.,  Bureau  of  Animal  In- 
dustry.    Bull.  No.  11. 

Returns  from  the  Ninth,  Tenth  and  Eleventh  Censuses,  Relating 
to  the  Production  of  Milk,  Butter  and  Cheese  on  the  Farm.  U.  S. 
Dept.  Agr.,  Report  of  the  Statistician,  No.  113,  pp.  115-118. 

General. 

Facts  About  Milk.     U.  S.  Dept.  Agr.,  Farmers'  Bull.  No.  42. 

The  Dairy  Industry  in  Denmark.  U.  S.  Dept.  Agr.,  Bureau  of 
Animal  Industry,  Bull.  No.  5. 

The  Creamery  Industry.     Nevada  Bull.  No.  16. 

Dairying.     South  Carolina  Bull.  No.  19. 

Dairying  in  California.  U.  S.  Dept.  Agr.,  Bureau  of  Animal  In- 
dustry, Bull.  No.  14. 

Dairy  Farming  in  Washington.     Washington  Bull.  No.  2,  pp.  23-27. 

The  Dairy  Industry  in  Nebraska,  South  Dakota  and  North  Dakota. 
CJ.  S.  Dept.  Agr.,  Bureau  of  Animal  Industry,  Bull.  No.  16. 


INDEX, 


PAGE 

Abnormal  fermentations 71 

Accumulator 123 

Accuracy    of    Babcock    test    glass- 
ware    57 

Acid,  boracic 79 

—  butyric 23 

—  capric 23 

—  caproic 23 

—  caprylic 23 

—  citric 26 

—  dioxystearic 23 

—  hydrochloric,  for  ripening  cream .  129 

—  lactic  25,  74,  130 

determination  of . .- 135,  261 

—  lauric 23 

—  myristie 22 

—  oleic 22 

—  palmitic 22 

—  salicylic 79 

—  stearic 22 

—  sulphuric 62 

—  test,  Manns' i:U 

Acini 3 

Act,  Filled  cheese 250,  276 

—  oleomargarine 255,  269 

Adams'  method 36 

Adjustable  separator 123 

Aeration  of  milk 86, 172 

Aerators,  milk 87 

Aerometer,  Soxhlet's 45 

Agricultural     Experiment     Station 

Bulletins 289 

mentioned 46 

Air  drainage  237 


PAGE 

23 

23 

71 

Alexandra  Jumbo  separator  . . . 

124 

Aliquot  milk  sampler 

60 

Alkali,  decinormal 

135,  261 

n 

135 

—  use  of  in  cleaning 

85 

Alkaline  tablets,  Farrington's . . 
81, 

135,  261 

Alpha  discs  or  plates 

....   119 

—  separator 

.  . . .   124 

Alveoli 

3 

.  . . .   179 

—  home-trade  cheese    

....200 

—  Neufehatel  cheese 

203 

66 

Analysis,  gravimetric 

35 

Angus,  J.  J.,  mentioned 

233 

Aniline  butter  color 

161 

Animal      excrement,     relation 

of 

bacteria  to 

77 

86 

161 

78 

Apparatus,  Fjord's  control 

..    ..45 

—  pasteurizing 

81 

Arnold,  L.  B.,  quoted 

104 

Arnold's  separator 

123 

Asbestos  method  of  determination 

of  fat 

36 

Ash  of  milk 

25 

Asses'  milk 

16 

(299) 


300 


Index 


PAGE 

Associated  dairying 250 

Ayrshire  milk 33 

B41 131 

Babcock,  Dr.  S.  M.,  mentioned  . .  47,  49 
quoted... 17,  95,  104, 166,  254 

—  asbestos  method 36 

—  formula  for  solids  not  fat 260 

—  test  49 

calibration  of  glassware 265 

details  52 

Bacillus 67 

—  acidi  lactici 73 

—  No.  41 131 

—  prodigiosus 72 

—  tubercle 80 

Bacteria 67 

—  in  milk 69 

—  relation  of  animal  excrement  to.  77 
dust  to 77 

—  —  to'bay  and  dried  forage 77 

Bad  flavors  in  milk 91 

Barber,  quoted 132 

B.  and  W.  test  bottle 54 

Beimling,  H.  F.,  mentioned 50 

—  test 50 

Bernstein,  A.,  mentioned 234 

Bichromate  of  potash  59 

Bitter  milk 71 

Black  specks  in  Babcock  test 63 

Blood,  relation  of  to  milk  secretion.  11 

"Bloody  bread  " 72 

Board  of  Health  lactometer 38,  259 

Boracie  acid 79 

Borden,  Gail,  Jr.,  mentioned 253 

Bottle,  Babcock  test 52 

Bottling  milk 90 

"  Breaking  "  of  butter 146 

Breed,  influence  of  on  composition 

of  milk 32 

Brie  cheese 225 

Brine-salting  butter 157 

Brown  separator,  medium 123 

Bulletins  and  reportslof  Agr.  Exp. 

Stations 289 

Buildings,  farm  dairy 245 


PAGE 

Burette 136 

Butter  accumulator 123 

—  and  cheese  factories,  combined.. 244 

—  "  breaking  "  of 146 

—  color 161 

—  composition  of  159 

—  estimation  of  fat  in,  by  Babcock 

test 56 

—  factories   236 

—  "  factory  " 257 

—  finish 162 

—  flavor 160 

—  granules,  size  of 151 

—  imitation  creamery 257 

Buttermilk 229 

—  characteristic    appearance  of 147 

—  separation  of,  from  butter 150 

Butter,  mottled  and  streaked 156 

—  packages 158 

—  packing  and  marketing 157 

—  prints 159 

—  "process" 257 

—  quality  of 159 

—  rancid 20 

—  renovated 257 

—  relation  of   lactic  acid  to  keep- 

ing quality 137 

wash-water  to  flavor 153 

to  texture 152 

—  salting 154 

—  scale  of  perfection 163 

—  sweet  cream 128,  137 

—  texture  of 128,  160 

—  washing 150 

—  white  specks  in 138 

—  working 153 

Butyric  acid  20-23 

—  fermentations 71,  76 

Butyrin 20 

Butyrometer 51 

Calibration  of  Babcock  test  glass- 
ware   57,  265 

Camembert  cheese 225 

Canadian  Club  cheese 209 

Capric  acid 23 

Caprilin 20 


Index 


301 


PAGE 
...    2C 


Caprin 

Caproic  acid 23 

Caproin 20 

Caprylic  acid 23 

Careno,  mentioned 26 

Casein 23 

-dried 230 

—  coagulation  of 1^^ 

—  formation  of ^ 

Caustic  potash 60 

-soda 60 

Cement  floors 230 

Centigrade  thermometer .259 

Centrifugal    force,    relation    of    to 

complete  creaming 115 

—  separation HI 

theory  of ^^^ 

—  system ^^ 

Cheddar  cheese 1"9 

Cheddar,  English 210 

Cheddaring   187 

Cheese  ^63 

—  American  home-trade  200 

Neufchatel   203 

—  and  butter  factories  combined.. 244 
225 


—  Brie 

—  Camembert 225 

-  Canadian  Club 209 

-  Cheddar    1'9 

-  Cheshire 216 

-  Club-house 209 

-  color  of 198 

—  composition  of  197 

—  cottage  

—  cream 


—  curing 


232 
,200 
,193 


_  _  rooms,  constniction  of 244 

—  D'Isiginy 227 

—  double  Gloucester 210 

-Edam  220 

—  EngUsh  210 

Cheddar  210 

—  estimation  of  fat  in,  by  Babcock 

test   56 

—  Derbyshire 218 

—  Dutch 232 


PAGE 

Cheese  Emmenthaler 219 

—  factories , 236 

—  —  arrangement  of 242 

—  filled,  law 276 

—  flavor  of 197 

—  "  flinty  break"    198 

—  food    233 

—  formation  of  rind 193 

—  Gloucester 210 

—  Gouda    224 

—  Gorgonzola 219 

—  Gruyere 219 

-hard    199 

—  imitation  Swiss 209 

—  Lancashire 218 

—  law,  filled 256 

—  Leicestershire 218 

—  Limburger - 207 

—  making,  cheddaring 187 

—  —  cooking   185 

cooling  milk  for 171 

curing 193 

cutting 183 

heating 185 

grinding   189 

loss  of  fat  in 170 

matting 187 

_  _  over-ripe  milk  in 196 

—  —  pressing 191 

quality  of  milk  for 164 

ripening  of  milk  for 172 


setting. 


,181 


salting 190 

undesirable  fermentations  in.  194 

use  of  starters 175 

-  Meadow  Sweet 209 

-  Neufchatel 203 

—  Parmesan 228 

—  Philadelphia  cream 207 


—  picnic. 


.203 


pineapple 203 


poisonous 


73 


Pont  L'Eveque 227 


—  pot 


.232 


PortduSalut 228 

prepared  209 


302 


Index 


PAGE 

Cheese  press  192 

—  qualities  of 197 

—  rind 198 

—  Roquefort 16,  224 

—  sage 202 

—  scale  of  perfection  for 198 

—  Schweitzer  219 

—  single  Gloucester 210 

—  skimmed  200,  256 

—  soft 199 

—  solids  concerned  in  making 163 

—  Square  cream 207 

—  Stilton  210 

—  stirred  curd 200 

—  Swiss 219 

—  texture  of 197 

—  truckle 203 

—  Wensleydale 219 

—  "wet,"  "sloppy,"  or  "leaky"  ..   ..202 

—  whey 232 

—  Wiltshire 210 

—  Young  America 203 

Cheshire    cheese 216 

Chloride  of  potash 25 

—  of  soda 25 

Chromogenic  fermentations 71 

Churn,  oil  test 42 

—  tests    41 

Churning 140 

—  amount  of  motion  necessary 145 

—  difficult 147 

—  dilution  of  cream 148 

—  kind  of  agitation  desirable 143 

—  relation  of  fat  globules  to 145 

of  ripeness  of  cream  to... 137, 141 

of  temperature  to 141 

—  —  of  viscosity  to 140 

—  rise  of  temperature  in 149 

Cistern,  milk 5 

Citric  acid 26 

Cleaning  tinware 84 

—  utensils 13 

Cleanliness 83 

Club-house  cheese 209 

Cloth  strainers 85 

Coagulation 164 


PAGE 

Coccus 67 

Cochran,  C.  B.,  mentioned 49 

Cochran's  method 49 

Cold  storage.. 258 

Columbia  separator 123 

Color  fermentations 71 

—  of  butter 160 

—  of  cheese 198 

Colostrum 9,  18 

—  composition  of 18 

—  corpuscles 18 

—  test  for 18 

Combined    butter    and    cheese  fac- 
tories   244 

Commercial  lactic  ferment 130 

Comparison  of  lactometer  scales 260 

—  of  thermometer  scales 259 

Composite  sampling 59 

Composition  of  butter 159 

—  of  cheese 197 

—  of  cream 97 

—  of  milk 17 

Concussion  in  churning 143 

Condensed  milk 253 

Conn  culture 132 

—  H.  W.,  mentioned 129,  131 

Connective  tissue 3 

Constituents  of  milk 16 

Construction  of  creameries 240 

Control  apparatus.  Fjord's 45 

—  of  fermentations 76 

—  of  milk  supply 93 

Cooking  the  curd 185 

Coolers,  milk 87 

Cornell  Univ.   Agr.   Expt.    Station, 

quoted 87,  106, 109,  111,  122,  124 

Cornevin,  quoted 17 

Correction  of    lactometer  for  tem- 
perature  260 

Cooley  system 103 

Cooling  milk  for  cheese  making 171 

Corpuscles,  colostrum 18 

Corrosive  sublimate 59 

Cottage  cheese 232 

Cows'  milk 16 

Cows,  number  in  United  States 248 


Index 


303 


PAGE 

Cows,  official  inspection  of 90 

Cream 97 

—  cheese 200 

Philadelphia 207 

—  —  square 207 

—  composition  of 97 

—  consistency  of 95 

—  degree  of  ripeness  necessary 134 

—  dilution  in  churning 148 

—  effect    of    different    degrees    of 

ripeness  on  churning 137 

—  estimation  of  fat  by  Babcock  test.  55 

—  for  consumption 94 

—  frothing  or  swelling 148 

—  gathering  system 41,  252 

—  glasses 36 

—  gauges 36 

—  over- ripened 138 

—  pasteiu-ized 95 

—  quality  of 96 

—  relation  of  ripeness  to  churning.. 141 
of  temperature  to  ripening — 133 

—  ripening 127 

—  screw 118 

—  separation  of 97 

—  standards  for 96 

—  test  bottles 54 

—  use  of  starter  in  ripening 130 

—  visco 96 

Creameries 236 

—  construction  of 240 

—  gathered  cream 252 

—  gravity  system 237 

—  ground  plan 239 

—  location  of 236 

—  pumping  system 238 

—  water  supply  of 241 

Creamery  butter,  imitation 257 

Creaming,  deep  setting 102 

—  efficiency  of  centrifugal  122 

—  effects  of  delayed  setting 105 

—  —  of  dilution  on 107 

—  losses  in  deep  setting 103 

in  shallow  pan 102 

—  necessity  for 99 

—  relation  of  centrifugal  force  to. . .  115 


PAGB 
Creaming,  relation  of  fat   globules 
to 100 

—  —  of  inflow  to  complete 116 

of  solids  not  fat  to 100 

of  temperature  to  centrifugal.  116. 

—  —  of  viscosity  of  milk  to 101 

—  shallow  pan 101 

—  systems  of 98 

—  theory  of  centrifugal 113 

of  deep  setting  system 103 

Creamometers 36 

Curd,  cutting 183 

—  grinding 189 

—  heating  or  cooking 185 

—  knives 184 

—  in  Babcock  test 62 

—  matting  or  cheddaring 187 

—  miU 189 

—  sink 187 

—  salting 190 

—  test,  Wisconsin 263 

Curdling,  sweet 71 

Curds,  fast-working 196 

—  floating 195 

—  gassy 195 

Curing  cheese 193 

—  rooms,  construction  of 244 

—  —  sub-earth  dtict  for 244 

Cutting  the  curd 183 

Dairy  buildings,  farm ,  .245 

—  laws 269 

the  New  York 282 

—  legislation 254 

—  markets 257 

—  statistics  249 

Dairying,  associated  . . .- 250 

Danish  separator,  large 123 

small 123 

—  Weston  separator 123 

Dean,  H.  H.,  quoted 89,  167 

Decinormal  alkali 135,  261 

Deep  setting  creaming 102 

system 98 

theory  of 103 

D'Isigny  cheese 227 


304 


Index 


PAGE 

DeLaval  lactocrite 45 

—  separator 124 

Delayed    setting,   effect    on    cream- 


ing. 


.105 


Derbyshire  cheese 218 

Detachable  neck  test  bottle 54 

Determination  of  lactic  acid 135,  261 

Development  of  the  factory  system. 241 

Devon  milk 33 

Dextrose 25 

Difficult  churning 147 

Dilution,  effect  of  on  creaming 107 

—  of  cream  in  churning 148 

—  separators Ill 

Dioxystearic  acid 23 

Disease  germs 71,  80 

—  relation  of  pasteurization  to 90 

Diseased  herds,  official  inspection  a 

prevention 90 

Disinfectants 78 

Double  Gloucester  cheese 210 

—  necked  test  bottle 54 

Dried  casein 230 

Ducts,  milk 3,  5 

Dust,  relation  of  bacteria  to 77 

Dutch  cheese 232 

Edam  cheese 220 

Effect  of  delayed  setting  on  cream- 
ing  105 

—  of  dilution  on  creaming 107 

Electricity  as  a  germicide 79 

Electrolysis 79 

Emmenthaler  cheese 219 

Emulsion 23,  97 

English  Cheddar  cheese 210 

—  cheese 210 

Essential  oils 20 

Estimation  of  solids  not  fat 65,  260 

—  of  total  solids 65 

Ewe's  milk 16 

Excrement,  animal,  relation  of  bac- 
teria to 77 

Experiment  Station  bulletins 289 

—  Stations,  mentioned 46 

Extract,  rennet 178 


PAGE 

Factories,  arrangement  of  cheese... 242 

—  butter  and  cheese 236 

—  combined  butter  and  cheese 244 

—  gathered  cream 252 

"  Factory  "  butter 257 

Factory  system,  development  of 251 

Fahrenheit  thermometer 259 

Failyer  and  Willard,  mentioned 47 

Failyer  and  Willard's  method 47 

Farm  dairy  buildings 245 

Farrington's  alkaline  tablets 

81,  135,  261 
Farrington,  E.  H.,  quoted  ..81,  131,  135 

Fast  working  curds 196 

Fat  as  a  basis  of  value  for  milk  in 
cheese  making 169 

—  globules 23 

relation  of,  to  churning 145 

size  of 23,  100 

—  loss  of,  in  cheese-making 170 

Fats 20 

—  effect  of  period  of  lactation  on..  27 

—  formation  of 8 

—  gravimetric  determination  of 35 

—  non-volatile 22 

—  volatile 20 

Ferment,  preparation  of  artificial.  .263 
Ferments,  lactic 130 

—  soluble 164 

Fermentations,  abnormal 71 

—  alcoholic 71 

—  butyric 71,  76 

—  chromogenic 71 

—  control  of 76 

—  detection  of 263 

—  germs  of 67 

—  lactic 71,73,  130.  171 

—  normal 71 

—  of  milk 71 

—  peptogenic 71,  75 

—  poisonous 73 

—  putrefactive 71,  75 

—  undesirable  in  cheese  making...  194 

Feser's  lactoscope 44 

Fibrin 23,24 

PiUed  cheese  law 256,  276 


Index 


305 


PAGE 

Finish  of  butter 162 

Fission 67 

Fjord's  control  apparatus 45 

Flavor  of  butter 160 

—  —  —  relation  of  wash  water  to.  .153 

—  of  cheese 197 

Fleischmann,  quoted 17,  234 

Fleshy  udder 3 

«  Flinty  break  "  of  cheese 198 

Floating  curds 195 

Floors,  cement 240 

Follicle,  ultimate 3,  6 

Food,  influence  on  composition  of 

milk 30 

Fore  milk  and  strippings 30 

Formalin 79 

Formation  of  cheese  rind 193 

Formula  for  solids  not  fat,  Bab- 
cock's  260 

—  Richmond's 260 

Forage,  relation  of  bacteria  to 77 

Fright,  effect  on  milk'secretion 14 

Frothing  of  cream 148 

Galactose 25 

Gases  in  milk 86 

"  Gassy  "  curds 195 

Gassy  ferments  iuNeufchatel  cheese. 204 

Gathered  cream  system 252 

Gerber's  test 50 

Germ  diseases 71 

Germs  of  disease 80 

—  of  fermentation 67 

Glasses,  cream 36 

Glassware,  calibration  of  Babeock 

test 265 

Globules,  fat 23 

Gloucester  cheese,  single  and  double. 210 

Glycerides 22 

Goats'  milk 16 

Gorgonzola  cheese 219 

Gouda  cheese 224 

Grain  of  butter 160 

Gravimetric  analysis 35 

Gravity  creaming 98,  99 

—  separators Ill 


PAGE 

Gravity    system    of   creamery   con- 
struction  237 

Grinding  the  curd 189 

Gruyere  cheese 219 

Gauges,  cream 36 

Guernsey  milk 33 

Gurler,  H.  B.,  quoted 132 

Hansen's  lactic  ferment 131 

Hard  cheeses 199 

Hay,  relation  of  bactex-ia  to 77 

Heating  the  curd 185 

Heeren's  pioscope 43 

Herds,  official  inspection  cf  diseased  90 

Holding  up  milk 5 

Holstein-Friesian  milk 33 

Home-trade  cheese 200 

Horizontal  separators 114 

Hot  iron  test 265 

Hydrochloric     acid     for     ripening 

cream  129 

Hydrometer 37 

Imitation  creamery  butter 257 

—  Swiss  cheese 209 

Indicator,  litmus 261 

—  phenolphthalein 261 

Infection,  prevention  of 76 

Inflow,    relation    of     to     complete 

creaming 116 

Iowa  Station  test 48 

Ironclad  tinware 83 

Iron,  phosphate  of 25 

Jersey  milk 33 

Jordan,  Dr.  W.  H. ,  quoted 107 

Jumbo   separator  124 

Keeping  quality,  relation  of  lactic 

acid  to 137 

Kephir 234 

Knives,  curd  184 

Koenig,  quoted 17 

Koumiss 16,  234 

Lactation  period,  effect  on  eompoai- 

tion  of  milk 27 

Lactic  acid  25.  74,  130 


306 


Index 


PAGE 

Lactic  acid,  determination  of. .  .135,  261 

relation  to  keeping  quality  of 

butter 137 

—  fermentations 71,  73,  130,  171 

—  ferments  130 

Lactobutyrometer 43 

Lactochrome 26 

Lactometer 37 

—  comparison  of  scales 38 

—  corrections  for  temperature.  .39,  260 

—  Board  of  Health 259 

—  Quevenne 260 

—  scales,  comparison  of 260 

Lactocrite 45 

Lactoprotein 26 

Lactoscope 44 

Lactose 25 

Lancashire  cheese 218 

Laurie  acid 23 

Laurin 20 

Law,  dairy 269 

—  filled  cheese 256,  276 

—  oleom  argarine 255,  269 

—  the  New  York  dairy 282 

"  Leaky"  cheese 202 

LeFeldt  and   Lentsch,  mentioned. .  .112 

Leffman  and  Beam,  mentioned 154 

Legal  standards  for  milk  . .  .93,  254,  269 

—  cream 96 

Legislation,  dairy  254 

Leicestershire  cheese 218 

Lentsch  and  LeFeldt,  mentioned  ...  112 

Limburger  cheese 207 

Lime,  phosphate  of  25 

Litmus  test 261 

Loss  of  fat  in  cheese  making 170 

Lymphatics   3 

Magnesia,  phosphate  of 25 

Males,  milk  from 10 

Mammae 1 

Mammalia 1 

Mammary  gland 1 

Manns,  A.  G.,  mentioned 134 

—  acid  test 134 

Marchand's  lactobutyrometer 43 


PAGE 

Mares'  milk 16 

Marketing  butter 157 

Markets,  dairy 257 

Marschall  rennet  test 174,  264 

Maternity,  effect  on  milk  secretion.    9 

Matting 137 

Meadow  Sweet  cheese 209 

Membrane,  formation  of,  in  cheese 

making 185 

Method  of  Failyer  and  Willard 47 

Metric  system 267 

Milch  Zeitung 123 

Milk,  aeration  of 86,  172 

—  aerators 87 

—  albuminoids  of 23 

—  ash  of 25 

—  asses 16 

—  Ayrshire 33 

—  bacteria 69 

—  bad  flavors  in 91 

—  bitter 71 

—  bottles 90 

—  cistern 5 

—  composition  of 17 

—  condensed 253 

—  constituents 16 

—  control  of  animal  over  secretion 

of  14 

—  coolers 87 

—  cooling  for  cheese  making 171 

—  defined 1 

—  Devon 33 

—  difference  in  first  and  last  drawn.  30 
in  night's  and  morning's 28 

—  ducts 3,  5 

—  duration  of  flow 11 

—  effect  of  breed  on  composition..  32 

—  —  —  age  on  composition 31 

of  period  of  lactation  on 27 

—  ewe's 16 

—  fats 20 

—  fermentations  of 71 

—  from  males 10 

—  from    organs    other    than    tno 

mammary  glau J 10 

—  from  virgin  animals 10 


Index 


307 


PAGE 

Milk,  gases  in 86 

—  goats' 16 

—  Guernsey 33 

—  liolding  up 5 

—  Holstein-Friesian 33 

—  influence  of  food  on  composition.  30 
Milking,  frequency  of 13 

—  importance  of  complete 12 

—  —  of  regularity 13 

—  rapidity  of 14 

Milk,  Jersey 33 

—  legal  standards  for 254,  269 

—  mare's .   16 

—  over-ripeness  for  cheese  making  .196 

—  paying  for,  according  to  percen- 

tage of  fat 169 

—  quality  of,  for  cheese  making 164 

—  relation  of  viscosity  to  churn- 

ing  140 

—  ripening  for  cheese  making 172 

—  ropy 71 

—  sampler,  Scovell's  aliquot 60 

—  selection  for  pasteurizing 82 

—  secretion 7 

—  —  control  of  atiimal  over 14 

effect  of  fright  on 14 

—  —  —  of  maternity  on 9 

—  —  —   of  pregnancy  on 12 

—  —  —  of  sexual  excitement  on  . . .  14 
relation  of  blood  to 11. 

—  —  —  of  nervous  organization  to.  14 

—  —  —  of  partiu'ition  to 9 

—  Short  Horn 33 

—  skimmed 229 

—  slimy 71 

—  solids 16 

concerned  in  making  cheese ..  163 

—  specific  gravity  of 19 

—  sterile 66,  70 

—  straining 85 

—  sugar 25,  231 

—  —  formation  of 8 

—  supply,  control  of 93 

—  tests,  Babcock 49 

—  —  Beimling 50 

butyrometer 51 


PAGE 

Milk  tests,  Cochran's 49 

—  —  Failyer  and  Willard's 47 

—  —  Gerber's 50 

—  —  history 36 

—  —  Iowa  Station 48 

Parsons' 48 

Short's 48 

—  thief 59,  60 

—  variations  in  quality 27 

—  viscosity  of 101 

Mm,  curd 189 

Molds  67 

Moni-ad,  J.  H.,  quoted 207,  219,  233 

Mourad's  rennet  test 174,  264 

Moore,  quoted 132 

Mottled  butter 156 

Myristic  acid 22 

Myseost 232 

^  alkali 135 

Nervous  organization,   relation  to 

milk  secretion 15 

Neufchatel  clieese,  American 203 

Neumann,  mentioned 60 

New  York  dairy  law 282 

Night's  and  morning's  milk,  differ- 
ence in  composition 28 

Nipple 2 

Nitrate  of  soda 60 

Non-volatile  fats 22 

Normal  fermentations 71 

Odor,  animal 86 

Official  inspection  of  cows 90 

Ohlsson's  test  bottle 54 

Oil  test  churn 42 

Oleic  acid 22 

Olein 22 

Oleomargarine  255 

—  law  255,  269 

Oliver,  John 17 

Optimum  temperature 68 

Over -ripened    cream,    bad    effects 

of 138 

Over- ripe  milk  in  cheese  making  . .  .196 
Oxidation  in  cream-ripening 129 


308 


Index 


PAGE 

Packages,  butter 158 

Packing  butter 157 

Palmitic  acid 22 

Palmitin 22 

Paper  coil  method,  Adams' 36 

—  parchment  159 

Parmesan  cheese 228 

Parsons,  C.  L.,  mentioned 48 

Parsons'  method 48 

Parturition,    relation    of    to    milk 

secretion 9 

Pasteurization  79 ,  90 

—  apparatus 81 

—  selection  of  milk  for 82,  202 

Pasteurized  cream .• 96 

Patrick,  Geo.  E.,  mentioned 48 

Paying  for  milk  according  to  per- 
centage of  fat 169 

Peptogenic  fermentations 71,  75 

Phenolphthalein 135,  261 

Philadelphia  cream  cheese 207 

Phosphate  of  iron 25 

—  of  lime 25 

—  of  magnesia 25 

—  of  potash 25 

Picnic  cheese 203 

Pineapple  cheese 203 

Pioscope  43 

Poisonous  fermentations 73 

Pont  L'Eveque  cheese 227 

Port  du  Salut  cheese  228 

Potash,  caustic 60 

—  phosphate  of 25 

Potassium  bichromate 59 

—  chloride 25 

Pot  cheese 232 

Preserv'aline 60 

Preserv'atives    in    composite    sam- 
pling   59 

Pregnancy,  effect  of  on  mUk  secre- 
tion   12 

Preparation  of  artificial  starter 263 

Prepared  cheese 209 

Press,  cheese 192 

Pressed  tinware 84 

Pressing  cheese 191 


PAGE 

Prevention  of  infection 76 

Primost 232 

Print  butter 159 

Process  butter 257 

Ptomaines 73 

Pumping  system  of  creamery  con- 
struction   238 

Putrefactive  fermentations 71,  75 

Quality  of  butter 159 

—  of  cream 96 

—  of  milk  for  cheese  making 164 

legal  standards  for 93 

Quevenne  lactometer. 38,  260 

Rancid  butter 20 

References 289 

Rennet 164,  176 

—  extract 178 

—  relation    of    temperature    to  ac- 

tivity of 177 

—  test 173,  264 

—  —  Marschall's 174 

—  —  Monrad's 174 

Renovated  butter. . . » 257 

Reports  and  bulletins  of  Agr.  Exp. 

Stations 289 

Richmond,  quoted  18 

Richmond's  formula  for  solids  not 

fat 260 

Rind  of  cheese 198 

formation  of 193 

Ripeness,  churning  cream  of  differ- 
ent degrees 137 

—  of  cream,  relation  to  churning. .  .141 

Ripening  cream 127 

amount  necessary 134 

—  —  relation  of  temperature  to 133 

use  of  starters  in 130 

—  of  milk  for  cheese  making 172 

Ropy  milk 71 

Roquefort  cheese 16,  224 

Rules  and  tests,  useful 259 

Russell,  H.  L.,  quoted 81,  95,  131 

Russian  separator 125 

Rusty  tinware 84 


Index 


309 


Sage  cheese . 
Salt 


PAGE 
...202 
...156 


Salting  butter 154 

—  cheese 190 

Salicylic  acid 79 

Sampler,  Scovell  aliquot  milk 60 

Scale  of  perfection  for  butter 163 

for  cheese 198 

Sehmierkase 232 

Schweitzer  cheese 219 

Scovell  aliquot  milk  sampler 60 

Secretion  of  milk 7 

Selecting  milk  for  pasteurizing 82 

Separation,  theory  of  centrifugal. .  .113 
Separator,  adjustable 123 

—  Alexander  Jumbo 124 

—  Alpha 124 

—  Arnold's 123 

—  Columbia 123 

—  Danish  Weston. 123 

—  De  Laval 124 

—  dilution Ill 

—  gravity Ill 

—  horizontal 114 

—  large  Danish 123 

—  mecha'l  contrivances  in  bowrof..ll9 

—  medium  Brown 12 J 

—  Sharpies'  Russian 125 

—  slime 115 

—  small  Danish 123 

—  system 98 

—  United  States 125 

—  Victoria .123 

Setting,  effect  of  delay  on  creaming.  105 

—  milk  for  cheese  making 181 

Sewers 241 

Sexual    excitement,    effect    of,    on 

milk  secretion 6 

Shallow  pan  creaming 101 

system 98 

Sharpies'  Russian  separator 125 

Short,  F.  G. ,  mentioned 47 

Short-horn  milk 33 

Short's  method 47 

Single  Gloucester  cheese 210 

Size  of  fat  globules 100 


PAGE 

Sink,  curd 187 

Skimmed  cheese 200,  256 

—  milk 329 

estimation  of  fat  byBabcock 

test 56 

test  bottle 54 

Skimmer 102 

Skimming 102 

Slime,  separator 115 

Slimy  milk 71 

"  Sloppy"  cheese 202 

Soda,  caustic 60 

Sodivim  chloride 25 

—  nitrate 60 

Soft  cheese 199 

Solids  concerned  in  making  cheese..  163 

—  estimation  of  total 65 

—  not  fat,  estimation  of 65.  260 

relation  to  creaming 100 

—  total,  determinatiom  of 35 

Sohible  ferments 164 

Soxhlet's  method 45 

Specific  gravity 19,  37 

Specks,  black,  in  Babcock  test 63 

Speed  of  bowl,  relation  of,  to  com- 
plete creaming 40,  116 

Sphincter  muscle 4,  5 

Spirillum 67 

Spore 68 

Square  cream  cheese 207 

Standards  for  cream 96 

for  milk,  legal 93,  254,  269 

"  Standing  up  "  quality  of  butter 128 

Starters 130,  175 

—  preparation  of 263 

"  State  Brands  " 256 

Statistics,  dairy 249 

Stearic  acid 22 

Sterile,  milk 66,  70 

Sterilization 79 

Stilton  cheese 210 

Stirred-curd  cheese 200 

Storch,  mentioned 131 

Strainers 85 

Straining  milk .., 85 

Streaked  butter 156 


310 


Index 


PAGE 

Strippings  and  fore  milk 30 

Sub-earth  duct  for  curing-rooms 244 

Sugar  of  milk 25.  231 

Sulphuric  acid 62 

Sunlight,  effect  on  cleanliness 84 

Surface  tension 23,  97 

Sweet  cream  butter 128,  137 

—  curdling 71 

Swelling  of  cream 148 

Swiss  cheese 219 

—  —  imitation 209 

System,  metric 267 

Tablets,  Farrington"s  alkaline ..  135,  261 

Taints,  to  detect 263 

Teat 2 

Temperature,  best  for  churning 141 

for  deep  setting  creaming 103 

—  —  for  shallow  pan  creaming 101 

—  —  for  washing  butter 151 

—  correction  for  lactometer 260 

—  effect  of,  on  activity  of  rennet. .  .177 

—  for  ripening  cream 133 

—  relation  of,    to  centrifugal    sep- 

aration   116 

—  —  of,  to  churning 141 

—  rise  of,  in  churning 149 

Testing  Babcock  glassware 57 

Tests  and  rules,  useful 259 

Test,  Babcock 49 

—  —  calibration  of  glassware 265 

—  Beimling 50 

—  bottle,  Babcock 54 

B.  and  W 54 

—  —  cream 54 

—  —  detachable  neck 54 

—  —  double-necked 54 

—  —  Ohlsson 54 

—  —  skimmed  milk 54 

—  butyrometer   51 

—  churn 41 

—  Cochran's 49 

—  Failyer  and  Willard's 47 

—  Gerber's 50 

—  history  of  milk 36 

—  hot  iron 265 

—  Iowa  Station 48 


PAGB 
Test,  litmus 261 

—  Manns'  acid 134 

—  Parsons' 48 

—  phenolphthalein 261 

—  rennet 173,  264 

—  Short's 47 

—  Wisconsin  curd 263 

Texture  of  butter 128,  160 

relation  of  wash-water  to..  152 

—  of  cheese 197 

Theory  of  centrifugal  separation..  .113 
Thermometer,  Fahrenheit 259 

—  Centrigrade 259 

—  scales,  comparison  of 259 

Tiemann,  mentioned 129 

Tinware,  ironclad 83 

—  pressed 84 

—  rusty 84 

—  washing 84 

Tissue,  connective 3 

Total  solids,  determination  of 35 

—  —  estimation  of 65,  260 

Truckle  cheese 203 

Turbine,  steam,  Babcock 53 

Tubercle  bacillus 80 

Tjrrotoxicon 73 

Udder 2 

Ultimate  follicle 3,  6 

United  States  separator 125 

type  of  separator 120 

Urea 26 

Useful  rules  and  tes  is 259 

Utensils,  cleaning 77 

Van  Slyke,  Dr.  L.  L.,  mentioned. . .  31 

quoted 165,  170 

Vermont  Agr.  Expt.  Station  quoted .  109 

Vessels,  cleaning 77 

Victoria  separator 123 

Virgin  animals,  milk  from 10 

Viscogen 95 

—  preparation  of 262 

Visco-cream 96 

Viscosity  of  milk 97 

relation  of,  to  churning 140 


Index 


311 


PAGE 

Viscosity  of  milk  relation  to  cream- 
ing   101 

Volatile  fats 20 

—  —  sovirce  of 21 

Von  Klenze,  mentioned 199 

Washing  butter 150 

-—  tinware 84 

Water  supply  of  creamerie3 241 

Wells 241 

Wensleydale  cheese 219 

«  Wet "  cheese 202 

Whey 229 


PAGE 

Whey  cheese 232 

Wheyn  234 

Wliite  specks  in  butter 138 

Williams,  Jesse,  mentioned 251 

Wiltshire  cheese 210 

Wire  strainers,  size  of 85 

Wisconsin  curd  test 263 

Woll,  F.  W.,  quoted 52 

Working  butter 153 

Yeasts 67 

Young  America  cheese 203 


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THE  SPRAYING  OF  PLANTS.  By  E.  G.  Lodeman,  late  of  Cornell  Uni- 
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T 


WORKS     BY    PROFESSOR     BAILEY 

HE  EVOLUTION  OF  OUR  NA- 
TIVE FRUITS.  By  L.  H.  BAILEY,  Pro^ 
fessor  of   Horticulture  in  the  Cornell  University. 

478    PACES -125    ILLUSTRATIONS  — $2.00 

In  this  entertaining  volume,  the  origin  and  de- 
velopment of  the  fruits  peculiar  to  North  America 
are  inquired  into,  and  the  personality  of  those  horti- 
cultural pioneers  whose  almost  forgotten  labors 
have  given  us  our  most  valuable  fruits  is  touched 
upon.  There  has  been  careful  research  into  the 
history  of  the  various  fruits,  including  inspection 
of  the  records  of  the  great  European  botanists  who 
have  given  attention  to  American  economic  botany. 
The  conclusions  reached,  the  information  presented, 
and  the  suggestions  as  to  future  developments,  can- 
not but  be  valuable  to  any  thoughtful  fruit-grower, 
while  the  terse  style  of  the  author  is  at  its  best  in 
his  treatment  of  the  subject. 

The  Evolution  of  our  Native  Fruits  discusses  The  Rise  of 
the  American  Grape  (Noi'th  America  a  Natural  Vineland,  Attempts 
to  Cultivate  the  European  Grape,  The  Experiments  of  the  Dufours, 
The  Branch  of  Promise,  John  Adlum  and  the  Catawba,  Rise  of 
Commercial  Viticulture,  Why  Did  the  Early  Vine  Experiments  Fail  I 
Synopsis  of  the  American  Grapes) ;  The  Strange  History  of  the  Mul- 
berries (The  Early  Silk  Industry,  The  "Multicaulis  Craze,") ;  Evolu- 
tion of  American  Plums  and  Cherries  (Native  Plums  in  General, 
The  Chickasaw,  Hortulana,  Marianna  and  Beach  Plum  Groups, 
Pacific  Coast  Plum,  Various  Other  Types  of  Plums,  Native  Cherries, 
Dwarf  Cherry  Group);  Native  Apples  (Indigenous  Species,  Amelio- 
ration has  begun);  Origin  of  American  Raspberry-growing  (Early 
American  History,  Present  Types,  Outlying  Types);  Evolution  of 
Blackberry  and  Dewberry  Culture  (The  High-bush  Blackberry  and 
Its  Kin,  The  Dewberries,  Botanical  Names);  Various  Types  of 
Berry-like  Fruits  (The  Gooseberry,  Native  Currants,  Juneberry, 
Buffalo  Berry,  Elderberry,  High-bush  Cranberry,  Cranberry,  Straw- 
berry); Various  Types  of  Tree  Fruits  (Persimmon,  Custard-Apple 
Tribe,  Thorn-Apples,  Nut-Fruits) ;  General  Remarks  on  the  Improve- 
ment of  our  Native  Fruits  (What  Has  Been  Done,  What  Probably 
Should  Be  Done). 


T 


WORKS    gy  PROFESSOR    BAILEY 

HE  SURVIVAL  OF  THE  UNLIKE: 

A  Collection  of  Evolution  Essays  Suggested 
by  the  Study  of  Domestic  Plants.    By  L.  H. 

BAILEY,    Professor  of    Horticulture    in    the  Cornell 
University. 

FOURTH  EDITION- 515    PAGES  — 22    ILLUSTRATIONS— $2.00 

To  those  interested  in  the  underlying  philosophy 
of  plant  life,  this  volume,  written  in  a  most  enter- 
taining style,  and  fully  illustrated,  will  prove  wel- 
come. It  treats  of  the  modification  of  plants  under 
cultivation  upon  the  evolution  theory,  and  its  atti- 
tude on  this  interesting  subject  is  characterized 
by  the  author's  well-known  originality  and  inde- 
pendence of  thought.  Incidentally,  there  is  stated 
much  that  will  be  valuable  and  suggestive  to  the 
working  horticulturist,  as  well  as  to  the  man  or 
woman  impelled  by  a  love  of  nature  to  horticul- 
tural pursuits.  It  may  well  be  called,  indeed,  a 
philosophy  of  horticulture,  in  which  all  interested 
may    find  inspiration  and  instruction. 

The  Survival  of  the  Unlike  comprises  thirty  essays  touching 
upon  The  General  Fact  and  Philosophy  of  Evolution  (The  Plant 
Individual,  Experimental  Evolution,  Coxey's  Army  and  the  Russian 
Thistle,  Recent  Progress,  etc.);  Expounding  the  Fact  and  Causes  of 
Variation  (The  Supposed  Correlations  of  Quality  in  Fruits,  Natural 
History  of  Synonyms,  Reflective  Impressions,  Relation  of  Seed- 
bearing  to  Cultivation,  Variation  after  Birth,  Relation  between 
American  and  Eastern  Asian  Fx'uits,  Horticultural  Geography,  Prob- 
lems of  Climate  and  Plants,  American  Fruits,  Acclimatization,  Sex 
in  Fruits,  Novelties,  Promising  Varieties,  etc.);  and  Tracing  the 
Evolution  of  Particular  Types  of  Plants  (the  Cultivated  Strawberry, 
Battle  of  the  Plums,  Grapes,  Progress  of  the  Carnation.  Petunia, 
The  Garden  Tomato,  etc.). 


CYCLOPEDIA  Of 
AMERICAN  nORTIClJLTURE 

COMPRISING  DIRECTIONS  FOR  THE  CULTIVATION  OF  HORTICULTURAL 
CROPS,  AND  ORIGINAL  DESCRIPTIONS  OF  ALL  THE  SPECIES  OF 
FRUITS,  VEGETABLES,  FLOWERS  AND  ORNAMENTAL  PLANTS  KNOWN 
TO    BE    IN     THE    MARKET    IN     THE     UNITED    STATES     AND     CANADA 

By  L.   H.   bailey 

ASSISTED   BY  MANY   EXPERT   CULTIVATORS  AND    BOTANISTS 

In  Four  Quarto  Volumes, 
Illustrated  with  over  Two  Thousand  Original  Engravings 

THIS  monumental  work,  the  most  comprehensive 
review  of  the  vegetable  world  yet  made  by  an 
American,  is  now  in  the  press.  Though  distinctly 
an  American  work,  not  onlj'  plants  indigenous  to 
the  Xorth  American  continent  are  mentioned,  but 
also  all  the  species  known  to  be  in  the  horticul- 
tural trade  in  Xorth  America,  of  whatever  origin. 
It  is  really  a  survey  of  the  cultivated  plants  of  the 
world. 

The  Editor,  Professor  L.  H.  Bailey,  has  been 
gathering  material  for  this  Cyclopedia  for  many 
years.  He  has  enlisted  the  cooperation  of  many 
men  of  attainments,  either  in  science  or  practice, 
and  the  Cyclopedia  has  the  unique  distinction  of 
presenting  for  the  first  time,  in  a  carefully  arranged 
and  perfectly  accessible  form,  the  best  knowledge  of 
the  best  specialists  in  America  upon  gardening, 
fruit-growing,   vegetable   culture,   forestry,   and   the 


like,  as  well  as  exact  botanical  information.  It  is 
all  fresh,  and  not  a  rehash  of  old  material.  No 
precedent  has  been  followed  ;  the  work  is  upon  its 
own  original  plan. 

Many  scientific  botanical  authors  of  justly  high 
repute  decline  to  give  attention  to  the  important 
characters  of  cultivated  plants,  confining  their  work 
to  the  species  in  the  original  forms  only.  Pro- 
fessor Bailey  takes  the  view  that  a  subject  of  com- 
mercial importance,  one  which  engages  the  attention 
and  affects  the  livelihood  of  thousands  of  bright 
people,  is  decidedly  worthy  the  investigation  of  the 
trained  botanist.  In  the  Cj'Clopedia  of  American 
Horticulture,  therefore,  very  full  accounts  are  given 
of  the  botanical  features  of  all  important  commercial 
plants,  as  the  apple,  cabbage,  rose,  etc.  At  the  same 
time,  practical  cultivators  submit  observations  upon 
culture,  marketing,  and  the  like,  and  frequently  two 
opinions  are  presented  upon  the  same  subject  from 
different  localities,  so  that  the  reader  may  have 
before  him  not  only  complete  botanical  information, 
but  very  fully  the  best  practice  in  the  most  favor- 
able localities  for  the  perfection  of  any  fruit  or 
vegetable  or  economic  plant. 

ILLISTRATIONS 

The  pictorial  character  of  the  work  is  likewise  nota- 
ble. There  are  nearly  three  thousand  illustrations, 
and  they  are  made  expressly  for  this  work,  either 
from  accurate  photographs  or  from  the  specimens. 
These  illustrations  have  been   drawn   by   competent 


horticultural  artists,  in  nearly  every  case  under  the; 
eye  of  the  Editor,  or  with  the  supervision  of  some 
one  of  the  sub-editors.     No  "trade"  cuts  are  used. 

[n  planning  the  illustrations,  artistic  effect  has 
been  kept  in  view,  and  while  no  drawing  is  used 
which  does  not  show  its  subject  with  perfect  scien- 
tific accuracy,  the  monotonous  so-called  "botanical" 
outlines,  often  made  from  lifeless  herbarium  speci- 
mens, are  notably  absent.  The  intention  is  to  show 
the  life  of  the  plant,  not  merely  its  skeleton. 

CONTRIBITORS,  SYSTEM,  ETC. 

As  above  mentioned,  the  contributors  are  men 
eminent  as  cultivators  or  as  specialists  in  the  various 
subjects.  The  important  articles  are  signed,  and  it 
is  expected  that  the  complete  work  will  include  fully 
5,000  signed  contributions  by  horticulturists,  culti- 
vators and  botanists. 

The  arrangement  is  alphabetical  as  to  the  genera, 
but  systematic  in  the  species.  A  very  simple  but 
complete  plan  of  key -letters  is  used,  and  the  whole 
arrangement  is  toward  ease  of  reference  as  well  as 
completeness  of  information.  To  each  large  genus 
there  is  a  separate  alphabetic  index. 

Important  commercial  subjects  are  treated  usually 
under  the  best  known  name,  whether  it  be  the 
scientific  or  "common"  designation.  Thus,  the  apple 
is  fully  discussed  as  apple,  rather  than  as  Pyrus 
Mains,  and  the  carnation  comes  into  view  in  the 
third  letter  of  the  alphabet,  not  as  Bianthus  Caryo- 
phyllus.     Carefully  edited   cross-references   make   it 


easy  to  find  any  desired  subject,  however,  in  the 
shortest  time. 

The  plan  of  presenting  the  full  details  of  cul- 
ture of  important  plants,  through  the  views  of 
acknowledged  practical  experts  upon  the  various 
subjects,  assures  the  great  value  of  the  book  to  the 
man  or  woman  who  is  obtaining  a  living  from 
horticultural  pursuits. 

A  special  feature  of  the  Cyclopedia  of  American 
Horticulture  is  its  wealth  of  bibliographic  reference. 
The  world's  horticultural  literature  has  been  thor- 
oughly searched,  and  most  carefully  indexed,  so  that 
the  student  will  find  citations  to  nearly  every  avail- 
able article  or  illustration  upon  any  subject  consulted. 

DETAILS  OF  PUBLICATION 

The  Cyclopedia  of  American  Horticulture  is  to 
be  completed  in  four  handsome  quarto  volumes, 
embracing  about  two  thousand  pages,  with  more 
than  that  number  of  original  illustrations.  It  is 
carefully  printed  upon  specially  made  paper  of  a 
permanent  character.  Vol.  I  (A  to  D,  509  pages, 
743  illustrations,  9  plates),  Vol.  H  (E  to  M,  544 
pages,  710  illustrations,  10  plates),  and  Vol.  HI  (N 
to  Q,  432  pages,  606  illustrations,  11  plates)  are  now 
ready,  and  the  last  volume  is  in  press. 

The  -work  is  sold  only  by  subscription,  and 
orders  will  be  accepted  for  the  full  set  only. 
Terms  and  further  information  may  be  had  of 
the   Publishers, 

THE    MACMILLAN    COMPANY 

No.  66   Fifth  Avenue  NEW    YORK 


WORKS    BY    PROFESSOR    BAILEY 

ESSONS  WITH  PLANTS:  Sugges- 
tions for  Seeing  and  Interpreting  Some  of 
the   Common    Forms   of  Vegetation.     By  l. 

H.  BAILEY,  Professor  of  Horticulture  in  the  Cornell 
University,  with  delineations  from  nature  by  W.  S. 
HOLDSWORTH,  of  the  Agricultural  College  of 
Michigan. 

SECOND  EDITION— 491  PACES— 446  ILLUSTRATIONS— 1  2  MO- 
CLOTH— $1.10  NET 

There  are  two  waj's  of  looking  at  nature.  The 
old  way,  which  you  have  found  so  unsatisfactory, 
was  to  classify  everything — to  consider  leaves,  roots, 
and  whole  plants  as  formal  herbarium  specimens, 
forgetting  that  each  had  its  own  story  of  growth 
and  development,  struggle  and  success,  to  tell. 
Nothing  stifles  a  natural  love  for  i)lants  more  effect- 
ually than  that  old  way. 

The  new  way  is  to  watch  the  life  of  every  grow- 
ing thing,  to  look  upon  each  plant  as  a  living 
creatm-e,  whose  life  is  a  story  as  fascinating  as  the 
story  of  any  favorite  hero.  "Lessons  with  Plants" 
is  a  book  of  stories,  or  rather,  a  book  of  plays,  for 
we  can  see  each  chapter  acted  out  if  we  take  the 
trouble  to  look  at  the  actors. 

"I  have  spent  some  time  inmost  delightful  examination  of  it,  and  the 
longer  I  look,  the  better  I  like  it.  I  find  it  not  only  full  of  interest,  but 
eminently  suggestive.  I  know  of  no  book  which  begins  to  do  so  much  to 
open  the  eyes  of  the  student— whether  pupil  or  teacher  — to  the  wealth  of 
meaning  contained  in  simple  plant  forms.  Above  all  else,  it  seems  to  be 
full  of  suggestions  that  help  one  to  learn  the  language  of  plants,  so  they 
may  talk  to  him."—  Darwin  L.  Bardwell,  Superintendent  of  Schools,  Bing- 
hainton. 

"It  is  an  admirable  book,  and  cannot  fail  both  to  awaken  interest  iu 
the  subject,  and  to  serve  as  a  helpful  and  reliable  guide  to  young  students 
of  plant  life.  It  will,  I  think,  fill  an  important  place  in  secondarj'  schools, 
and  comes  at  an  opportune  time,  when  helps  of  this  kind  are  needed  and 
eagerly  sought."— Professor  V.  M.  Spaldinu,  University  of  Michigan. 

FIRST    LESSONS    WITH    PLANTS 

An  Abridgement  of  the  above.  117  pages — 116  illustra- 
tions— 40  cents  net. 


